發(fā)布時(shí)間: 2024年12月23日 23:46
TPO是我們常用的托福模考工具，對(duì)我們的備考很有價(jià)值，下面我給大家?guī)?lái)托福閱讀TPO16(試題+答案+譯文)第2篇:Development of the Periodic Table。
托福閱讀原文
The periodic table is a chart that reflects the periodic recurrence of chemical and physical properties of the elements when the elements are arranged in order of increasing atomic number (the number of protons in the nucleus). It is a monumental scientific achievement, and its development illustrates the essential interplay between observation, prediction, and testing required for scientific progress. In the 1800's scientists were searching for new elements. By the late 1860's more than 60 chemical elements had been identified, and much was known about their descriptive chemistry. Various proposals were put forth to arrange the elements into groups based on similarities in chemical and physical properties. The next step was to recognize a connection between group properties (physical or chemical similarities) and atomic mass (the measured mass of an individual atom of an element). When the elements known at the time were ordered by increasing atomic mass, it was found that successive elements belonged to different chemical groups and that the order of the groups in this sequence was fixed and repeated itself at regular intervals. Thus when the series of elements was written so as to begin a new horizontal row with each alkali metal, elements of the same groups were automatically assembled in vertical columns in a periodic table of the elements. This table was the forerunner of the modern table.
When the German chemist Lothar Meyer and (independently) the Russian Dmitry Mendeleyev first introduced the periodic table in 1869-70, one-third of the naturally occurring chemical elements had not yet been discovered. Yet both chemists were sufficiently farsighted to leave gaps where their analyses of periodic physical and chemical properties indicated that new elements should be located. Mendeleyev was bolder than Meyer and even assumed that if a measured atomic mass put an element in the wrong place in the table, the atomic mass was wrong. In some cases this was true. Indium, for example, had previously been assigned an atomic mass between those of arsenic and selenium. Because there is no space in the periodic table between these two elements, Mendeleyev suggested that the atomic mass of indium be changed to a completely different value, where it would fill an empty space between cadmium and tin. In fact, subsequent work has shown that in a periodic table, elements should not be ordered strictly by atomic mass. For example, tellurium comes before iodine in the periodic table, even though its atomic mass is slightly greater. Such anomalies are due to the relative abundance of the "isotopes" or varieties of each element. All the isotopes of a given element have the same number of protons, but differ in their number of neutrons, and hence in their atomic mass. The isotopes of a given element have the same chemical properties but slightly different physical properties. We now know that atomic number (the number of protons in the nucleus), not atomic mass number (the number of protons and neutrons), determines chemical behavior.
Mendeleyev went further than Meyer in another respect: he predicted the properties of six elements yet to be discovered. For example, a gap just below aluminum suggested a new element would be found with properties analogous to those of aluminum. Mendeleyev designated this element "eka-aluminum" (eka is the Sanskrit word for "next") and predicted its properties. Just five years later an element with the proper atomic mass was isolated and named gallium by its discoverer. The close correspondence between the observed properties of gallium and Mendeleyev’s predictions for eka-aluminum lent strong support to the periodic law. Additional support came in 1885 when eka-silicon, which had also been described in advance by Mendeleyev, was discovered and named germanium.
The structure of the periodic table appeared to limit the number of possible elements. It was therefore quite surprising when John William Strut (Lord Rayleigh, discovered a gaseous element in 1894 that did not fit into the previous classification scheme. A century earlier, Henry Cavendish had noted the existence of a residual gas when oxygen and nitrogen are removed from air, but its importance had not been realized. Together with William Ramsay, Rayleigh isolated the gas (separating it from other substances into its pure state) and named it argon. Ramsay then studied a gas that was present in natural gas deposits and discovered that it was helium, an element whose presence in the Sun had been noted earlier in the spectrum of sunlight but that had not previously been known on Earth. Rayleigh and Ramsay postulated the existence of a new group of elements, and in 1898 other members of the series (neon, krypton, and xenon) were isolated.
托福閱讀試題
1.The phrase interplay in the passage (paragraph 1) is closest in meaning to
A.sequence
B.interpretation
C.requirement
D.interaction
2.According to paragraph 1, what pattern did scientists notice when the known elements were written in order of increasing atomic mass?
A.The elements of the group of alkali metals were the first elements in the order of increasing atomic mass.
B.Repetition of the same atomic masses for elements in different groups appeared.
C.Elements with similar chemical properties appeared in the listing at regular intervals.
D.Elements were chemically most similar to those just before and after them in the order.
3.In paragraph 2, what is the author's purpose in presenting the information about the decision by Meyer and Mendeleyev to leave gaps in the periodic table?
A.To illustrate their confidence that the organizing principles of the periodic table would govern the occurrence of all chemical elements
B.To indicate that some of their analyses of periodic physical and chemical properties were later found to be wrong
C.To support the idea that they were unwilling to place new elements in the periodic table
D.To indicate how they handled their disagreement about where to place new elements
4.What reason does the author provide for the claim that Mendeleyev was bolder than Meyer?(in paragraph 2)
A.Mendeleyev corrected incorrect information Meyer had proposed.
B.Mendeleyev assumed that some information believed to be true about the elements was incorrect.
C.Mendeleyev argued that Meyer had not left enough gaps in the periodic table.
D.Mendeleyev realized that elements were not ordered by atomic mass in the periodic table.
5.According to paragraph 2, why did Mendeleyev suggest changing the atomic mass of indium?
A.Because indium did not fit into the periodic table in the place predicted by its atomic mass.
B.Because there was experimental evidence that the atomic mass that had been assigned to indium was incorrect.
C.Because there was an empty space between cadmium and tin in the periodic table.
D.Because the chemical properties of indium were similar to those of arsenic and selenium.
6.It can be inferred from paragraph 2 that tellurium comes before iodine in the periodic table even though tellurium's atomic mass is slightly greater because
A.iodine is less common than tellurium
B.both iodine and tellurium have no isotopes
C.the chemical behavior of tellurium is highly variable
D.the atomic number of tellurium is smaller than that of iodine
7.The phrase “abundance” in the passage (paragraph 2) is closest in meaning to
A.weight
B.requirement
C.plenty
D.sequence
8.The phrase “analogous to” in the passage (paragraph 3) is closest in meaning to
A.predicted by
B.expected of
C.similar to
D.superior to
9.Paragraph 3 suggests that Mendeleyev predicted the properties of eka-aluminum on the basis of
A.the atomic mass of aluminum
B.the position of the gap in the periodic table that eka-aluminum was predicted to fill
C.the similarity of eka-aluminum to the other five missing elements
D.observation of the properties of gallium
10.It can be inferred from paragraph 3 that the significance of the discovery of gallium was that it supported which of the following?
A.The idea that aluminum was correctly placed in the periodic table.
B.Mendeleyev's prediction that eka-silicon would be discovered next.
C.The organizing principle of the periodic table.
D.The idea that unknown elements existed.
11.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage (paragraph 4)? Incorrect choices change the meaning in important ways or leave out essential information.
A.Ramsay found evidence of helium in the spectrum of sunlight before he discovered that the element was also contained in natural gas deposits on Earth.
B.Ramsay thought he had discovered a new element present in natural gas deposits, but he was wrong since that element had been previously observed elsewhere on Earth.
C.After Ramsay had discovered a new element, called helium, in natural gas deposits on Earth, he also found evidence of its presence in the Sun.
D.Ramsay later discovered that helium, an element that was already known to be present in the Sun, was also present in natural gas deposits on Earth.
12.The word “postulated” in the passage (paragraph 4) is closest in meaning to
A.hypothesized
B.discovered
C.reported
D.generated
13. Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit? It was a natural Idea to break up the series of elements at the points where the sequence of chemical groups to which the elements belonged began to repeat itself.
Paragraph1: The periodic table is a chart that reflects the periodic recurrence of chemical and physical properties of the elements when the elements are arranged in order of increasing atomic number (the number of protons in the nucleus). It is a monumental scientific achievement, and its development illustrates the essential interplay between observation, prediction, and testing required for scientific progress. In the 1800's scientists were searching for new elements. By the late 1860's more than 60 chemical elements had been identified, and much was known about their descriptive chemistry. Various proposals were put forth to arrange the elements into groups based on similarities in chemical and physical properties. ■【A】The next step was to recognize a connection between group properties (physical or chemical similarities) and atomic mass (the measured mass of an individual atom of an element). ■【B】When the elements known at the time were ordered by increasing atomic mass, it was found that successive elements belonged to different chemical groups and that the order of the groups in this sequence was fixed and repeated itself at regular intervals. ■【C】Thus when the series of elements was written so as to begin a new horizontal row with each alkali metal, elements of the same groups were automatically assembled in vertical columns in a periodic table of the elements. ■【D】This table was the forerunner of the modern table.
14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
The periodic table introduced by Meyer and Mendeleyev was the forerunner of the modern table of elements.
A.Lord Rayleigh provided evidence that the structure of the I—Ramsay and Lord Rayleigh challenged the importance of the periodic table limited the potential number of elements.
B.Chemical research that Henry Cavendish had done a century earlier.
C.Isotopes of a given element have exactly the same physical properties, but their chemical properties are slightly different.
D. Mendeleyev and Meyer organized the known elements into a F chart that revealed periodic recurrences of chemical and physical properties.
E.Mendeleyev's successful prediction of the properties of then- r unknown elements lent support to the acceptance of the periodic law.
F.In the 1890's, Ramsay and Lord Rayleigh isolated argon and proposed the existence of a new series of elements.
托福 閱讀答案
1.interplay相互作用，所以D的interaction正確。從單詞本身看，inter表示在……之間，play是起到什么什么作用，所以interplay是相互作用。原句說(shuō)觀察、預(yù)測(cè)與實(shí)驗(yàn)相互作用，所以答案是interaction，A順序B解釋C要求都錯(cuò)。
2.以increasing atomic mass做關(guān)鍵詞定位至倒數(shù)第三句，說(shuō)把元素按照原子量增加的順序排布，發(fā)現(xiàn)相鄰元素屬于不同的族，族的順序是固定的，每隔固定數(shù)量的元素會(huì)重現(xiàn)。所以正確答案是C。A的alkali metals，B的same atomic mass原文都沒(méi)說(shuō);D說(shuō)相鄰元素性質(zhì)相近與原文相反。
3.修辭目的題，先找到兩個(gè)人名，說(shuō)兩個(gè)人都非常有遠(yuǎn)見(jiàn)，在周期表中給沒(méi)發(fā)現(xiàn)的元素留了空隙，也就是A說(shuō)的他們足夠自信認(rèn)為元素周期律適用于所有元素;B的wrong和C的unwilling都跟原文說(shuō)反;D的disagreement原文沒(méi)說(shuō)。
4.修辭目的題，先找到兩個(gè)人名，說(shuō)門捷列夫比梅伊爾更膽兒大，他推測(cè)如果用來(lái)在周期表中排序的原子量與元素周期律互相沖突的時(shí)候，就說(shuō)明原子量錯(cuò)了，也就是選項(xiàng)B說(shuō)的門捷列夫認(rèn)為以前被大家所認(rèn)識(shí)到的一些東西是錯(cuò)的。兩個(gè)人的意見(jiàn)是一樣的，只是門捷列夫更進(jìn)一步，所以A和C說(shuō)兩者的意見(jiàn)有差異不對(duì);D說(shuō)不是按原子量排序的錯(cuò)。
5.以changing the atomic mass of indium做關(guān)鍵詞定位至第六句，說(shuō)由于元素周期表中砷和硒之間沒(méi)有空位，所以銦的原子量是錯(cuò)的。因?yàn)榍懊嬲f(shuō)如果原子量把元素放錯(cuò)了位置，就說(shuō)明原子量是錯(cuò)的，后一句是為了證明這個(gè)觀點(diǎn)的，所以答案是A。B的experimental evidence和D的化學(xué)性質(zhì)相似原文都沒(méi)說(shuō);C有space與原文相反。
6.以tellerium coms before iodine做關(guān)鍵詞定位至倒數(shù)第五句for example處，但這句話只是一個(gè)例子，所以往前看，說(shuō)元素不應(yīng)該嚴(yán)格按照原子量排列，而且最后一句又說(shuō)決定元素化學(xué)性質(zhì)的是原子序數(shù)，不是原子量，也就是應(yīng)該按照原序數(shù)量排列，所以答案D正確。A誰(shuí)common誰(shuí)不common，B有沒(méi)有同位素還有C的化學(xué)性質(zhì)多變沒(méi)有信息能推出。
7.abundance豐度，答案是plenty。原句說(shuō)這種異常，也就是盡管原子量大卻排在前面這種異常是由于同位素的什么，然后后面就解釋每種同位素的原子序數(shù)相同，但中子數(shù)不同，導(dǎo)致原子量不同，猜到每種同位素的多少不同，所以答案plenty，B要求D順序明顯不對(duì);A重量不同原文已經(jīng)直接說(shuō)了不用再說(shuō)一遍。
8.analogous to可類比的，相似的，所以答案similar to正確。原句說(shuō)鋁元素之下的空格表明一個(gè)性質(zhì)與鋁怎么樣的元素的存在，前文都說(shuō)了相鄰的元素屬于不同的族，而且族會(huì)相隔固定數(shù)目的元素出現(xiàn)，而且根據(jù)常識(shí)也知道元素周期表中上下兩元素性質(zhì)相似，所以答案是similar。A實(shí)現(xiàn)預(yù)測(cè)的是人，不是鋁元素的性質(zhì);B期待不靠譜;D誰(shuí)比誰(shuí)好原文沒(méi)說(shuō)。
9.以eka-aluminum做關(guān)鍵詞定位至第三句，但這句話只說(shuō)了預(yù)測(cè)了eka的性質(zhì)，沒(méi)說(shuō)根據(jù)什么預(yù)測(cè)的，看上一句，說(shuō)eka是鋁之下的那個(gè)空格里的元素，而且跟鋁性質(zhì)相似，所以答案是B，eka要填的那個(gè)空格。A鋁的原子量C另外五個(gè)沒(méi)發(fā)現(xiàn)的元素D的gallium原文都沒(méi)說(shuō)。
10.gallium做關(guān)鍵詞定位至倒數(shù)第三句，但這句話只是說(shuō)命名為GA，沒(méi)說(shuō)支持什么，往下看說(shuō)GA的發(fā)現(xiàn)支持了元素周期律，而問(wèn)題剛好是問(wèn)GA的發(fā)現(xiàn)支持了什么，所以答案是C，元素周期表的組成規(guī)律，也就是元素周期律。
11.原文的結(jié)構(gòu)是R研究了一種氣體，并且發(fā)現(xiàn)這種氣體是氦，所以答案是D。A完全搞亂了原文的結(jié)構(gòu)，氦在太陽(yáng)光譜中不是R發(fā)現(xiàn)的;B的轉(zhuǎn)折關(guān)系錯(cuò);C和A的錯(cuò)誤相似，氦在太陽(yáng)光譜中不是R發(fā)現(xiàn)的。
12.postulate推斷，推測(cè)，所以hypothesize正確。原句說(shuō)這兩個(gè)人怎么樣一個(gè)新的元素族的存在，接著后面的人分離出了這些元素，既然是后面的人分離的，discover和report就不對(duì)，因?yàn)檫@兩個(gè)詞有他們兩個(gè)發(fā)現(xiàn)的意思;generate完全不對(duì)，這兩個(gè)人不能產(chǎn)生元素。
13.三個(gè)過(guò)渡點(diǎn)，分別是名詞chemical groups，名詞sequence和動(dòng)詞詞組repeat itself，這幾個(gè)點(diǎn)都可以確定B或者C是答案，但B前后的atomic mass說(shuō)明兩句話的過(guò)渡是非常緊密的，所以B被排除，答案是C。
14.Lord選項(xiàng)錯(cuò)，原文沒(méi)說(shuō)他的研究提供了元素周期表限制元素?cái)?shù)量的證據(jù)，不選。Ramsay and Lord選項(xiàng)錯(cuò)，原文沒(méi)說(shuō)他們倆挑戰(zhàn)了卡文迪許，不選。Isotopes選項(xiàng)是原文第二段中的一個(gè)細(xì)節(jié)，不選。Mendeleyev and Meyer選項(xiàng)對(duì)應(yīng)原文第一段后半部分，正確。Mendeleyev’s選項(xiàng)對(duì)應(yīng)原文第三段最后兩句，正確。In the 1890’s選項(xiàng)對(duì)應(yīng)全文最后一句話，正確。
托福閱讀譯文
元素周期表是按原子序數(shù)(元素原子核中質(zhì)子的數(shù)量)由小到大依次排列，反映化學(xué)周期性和元素的物理特征的圖表。這一科學(xué)發(fā)現(xiàn)具有里程碑的意義，它進(jìn)一步證明了科學(xué)探索過(guò)程中觀察、預(yù)測(cè)和實(shí)證之間的根本聯(lián)系。19世紀(jì)一開始，科學(xué)家們不斷探索新的元素。到19世紀(jì)60年代后期，已經(jīng)發(fā)現(xiàn)了60種以上的化學(xué)元素，而許多描述性化學(xué)被認(rèn)知。人們提出各種建議，認(rèn)為該基于化學(xué)和物理特征的相似性將化學(xué)元素排列成組。他們接下來(lái)又證實(shí)了元素的族群特性(物理或是化學(xué)相似性)和原子質(zhì)量(一種元素的單個(gè)原子的測(cè)量質(zhì)量)之間存在聯(lián)系。當(dāng)時(shí)元素還是按照原子質(zhì)量從小到大排列，人們發(fā)現(xiàn)，一些具備連續(xù)性的元素卻分屬不同的化學(xué)組，并且發(fā)現(xiàn)在這種排列方式下，元素群組的順序是固定的且定期重復(fù)。因此，當(dāng)每一新行都以堿性金屬元素開始并逐步將這一系列的元素排列出來(lái)時(shí)，元素周期表中同一組中的元素就會(huì)自動(dòng)歸入一個(gè)垂直縱列中。這個(gè)表格就是現(xiàn)代元素周期表的雛形。
當(dāng)?shù)聡?guó)化學(xué)家邁耶(Lother Meyer)和(彼此獨(dú)立的)俄國(guó)化學(xué)家門捷列夫在1869年到1870年間首次發(fā)布元素周期表時(shí)，有三分之一的天然化學(xué)元素還沒(méi)被發(fā)現(xiàn)。然而這兩位化學(xué)家都極富遠(yuǎn)見(jiàn)，他們?cè)谥芷诒砩狭舭?，?duì)元素物理性和化學(xué)性的分析空白處還有新的元素有待發(fā)現(xiàn)。門捷列夫比邁耶更為大膽，他甚至做出假設(shè)，如果周期表按原子質(zhì)量排列，但元素位置不對(duì)的話，那么原子質(zhì)量也是錯(cuò)的。在某些情況下，這個(gè)設(shè)想是正確的。以銦為例，先前測(cè)量出銦的原子質(zhì)量在砷和硒之間。但是因?yàn)樵谥芷诒碇羞@兩個(gè)元素之間沒(méi)有縫隙，由此門捷列夫提出銦的原子質(zhì)量變?yōu)榻厝徊煌囊粋€(gè)值，這樣就可以將其置于鎘和錫之間的空位。事實(shí)上，接下來(lái)的研究表明，元素周期表中元素不能嚴(yán)格按照原子質(zhì)量排列。例如，盡管碲的原子質(zhì)量比碘略大，但在元素周期表中，它卻排在碘前面。出現(xiàn)這種反?，F(xiàn)象，主要是因?yàn)橄鄬?duì)豐富的“同位素 ”或者各種元素的多樣性。同一元素的所有同位素具有相同的質(zhì)子數(shù)，但中子數(shù)不同，因此它們的原子質(zhì)量也不一樣。一個(gè)特定元素的同位素具有相同的化學(xué)特征，但在物理性質(zhì)上有一些細(xì)微差異?，F(xiàn)在我們知道，是原子數(shù)目(原子核中質(zhì)子的數(shù)量)而非原子質(zhì)量(質(zhì)子和中子的數(shù)量)決定著元素的化學(xué)性質(zhì)。
門捷列夫在另一個(gè)研究上也比邁耶更為深入：他預(yù)測(cè)還有六種元素的性質(zhì)待被發(fā)現(xiàn)。例如，就在鋁下面有一個(gè)空位，這表明還有一個(gè)性質(zhì)和鋁類似的新元素存在。門捷列夫?qū)⒃撛囟x為“鋁下元素 ”(eka是梵語(yǔ)詞，意思是 “下一個(gè)”)并且還預(yù)測(cè)了其性質(zhì)。僅僅5年之后，原子質(zhì)量相吻合的元素就被分離出來(lái)，發(fā)現(xiàn)者將其命名為“鎵”。鎵所表現(xiàn)出的特性和門捷列夫?qū)Α颁X下元素”的預(yù)測(cè)一一對(duì)應(yīng)，這為元素法則提供了一個(gè)強(qiáng)有力的依據(jù)。還有一個(gè)例證，1885年發(fā)現(xiàn)“硅下元素”，同樣為門捷列夫所預(yù)測(cè)，后來(lái)命名為鍺。
元素周期表的框架似乎限制了可能存在的元素?cái)?shù)量。因此，當(dāng)約翰?威廉姆?斯特拉特(瑞利男爵)，在1894年發(fā)現(xiàn)一種氣態(tài)元素不能適應(yīng)之前的元素表時(shí)會(huì)非常驚訝。一個(gè)世紀(jì)以前，亨利?卡文迪許就注意到，當(dāng)氧氣和氮?dú)鈴目諝庵斜灰瞥笕匀挥袣堄鄽怏w存在，但當(dāng)時(shí)沒(méi)人意識(shí)到其中的重要性。瑞利和威廉?拉姆齊一道，共同分離出一種氣體(將之與其他物質(zhì)隔離并存于一個(gè)真空環(huán)境)并將其命名為氬。拉姆齊經(jīng)過(guò)研究又發(fā)現(xiàn)了另一種存在于自然界中的氣體元素——氦，該元素在太陽(yáng)中存在，并且很早就被發(fā)現(xiàn)存在于太陽(yáng)光譜中，但是之前并沒(méi)有在地球上找到過(guò)。瑞利和拉姆齊做出假設(shè)，認(rèn)為存在一組新元素，1898年，這一系列元素中的其他元素(氖，氪，氙)也被成功分離出來(lái)。
具有相同質(zhì)子數(shù)，不同中子數(shù)(或不同質(zhì)量數(shù))同一元素的不同核素互為同位素(Isotopes)。
Eka是一個(gè)用來(lái)為在元素周期表中位于某個(gè)元素下面的位置的化學(xué)元素命名的前綴。前綴eka-尤其用于命名尚未發(fā)現(xiàn)的元素。例如，在發(fā)現(xiàn)鍺以前它被稱為硅下元素(eka-硅，ekasilicon)。
托福閱讀TPO16(試題+答案+譯文)第2篇相關(guān) 文章 ：
TPO是我們常用的托福模考工具，對(duì)我們的備考很有價(jià)值，下面我給大家?guī)?lái)托福閱讀TPO20(試題+答案+譯文)第3篇:Fossil Preservation。
托福閱讀原文
【1】When one considers the many ways by which organisms are completely destroyed after death, it is remarkable that fossils are as common as they are. Attack by scavengers and bacteria, chemical decay, and destruction by erosion and other geologic agencies make the odds against preservation very high. However, the chances of escaping complete destruction are vastly improved if the organism happens to have a mineralized skeleton and dies in a place where it can be quickly buried by sediment. Both of these conditions are often found on the ocean floors, where shelled invertebrates (organisms without spines) flourish and are covered by the continuous rain of sedimentary particles. Although most fossils are found in marine sedimentary rocks, they also are found in terrestrial deposits left by streams and lakes. On occasion, animals and plants have been preserved after becoming immersed in tar or quicksand, trapped in ice or lava flows, or engulfed by rapid falls of volcanic ash.
【2】The term "fossil" often implies petrifaction, literally a transformation into stone. After the death of an organism, the soft tissue is ordinarily consumed by scavengers and bacteria. The empty shell of a snail or clam may be left behind, and if it is sufficiently durable and resistant to dissolution, it may remain basically unchanged for a long period of time. Indeed, unaltered shells of marine invertebrates are known from deposits over 100 million years old. In many marine creatures, however, the skeleton is composed of a mineral variety of calcium carbonate called aragonite. Although aragonite has the same composition as the more familiar mineral known as calcite, it has a different crystal form, is relatively unstable, and in time changes to the more stable calcite.
【3】Many other processes may alter the shell of a clam or snail and enhance its chances for preservation. Water containing dissolved silica, calcium carbonate, or iron may circulate through the enclosing sediment and be deposited in cavities such as marrow cavities and canals in bone once occupied by blood vessels and nerves. In such cases, the original composition of the bone or shell remains, but the fossil is made harder and more durable. This addition of a chemically precipitated substance into pore spaces is termed "permineralization."
【4】Petrifaction may also involve a simultaneous exchange of the original substance of a dead plant or animal with mineral matter of a different composition. This process is termed " replacement" because solutions have dissolved the original material and replaced it with an equal volume of the new substance. Replacement can be a marvelously precise process, so that details of shell ornamentation, tree rings in wood, and delicate structures in bone are accurately preserved.
【5】Another type of fossilization, known as carbonization, occurs when soft tissues are preserved as thin films of carbon. Leaves and tissue of soft-bodied organisms such as jellyfish or worms may accumulate, become buried and compressed, and lose their volatile constituents. The carbon often remains behind as a blackened silhouette.
【6】Although it is certainly true that the possession of hard parts enhances the prospect of preservation, organisms having soft tissues and organs are also occasionally preserved. Insects and even small invertebrates have been found preserved in the hardened resins of conifers and certain other trees. X-ray examination of thin slabs of rock sometimes reveals the ghostly outlines of tentacles, digestive tracts, and visual organs of a variety of marine creatures. Soft parts, including skin, hair, and viscera of ice age mammoths, have been preserved in frozen soil or in the oozing tar of oil seeps.
【7】The probability that actual remains of soft tissue will be preserved is improved if the organism dies in an environment of rapid deposition and oxygen deprivation. Under such conditions, the destructive effects of bacteria are diminished. The Middle Eocene Messel Shale (from about 48 million years ago) of Germany accumulated in such an environment. The shale was deposited in an oxygen-deficient lake where lethal gases sometimes bubbled up and killed animals. Their remains accumulated on the floor of the lake and were then covered by clay and silt. Among the superbly preserved Messel fossils are insects with iridescent exoskeletons (hard outer coverings), frogs with skin and blood vessels intact, and even entire small mammals with preserved fur and soft tissue.
托福閱讀試題
1.The word "agencies" in the passage (paragraph 1) is closest in meaning to
A.combinations.
B.problems.
C.forces.
D.changes.
2.In paragraph 1, what is the author's purpose in providing examples of how organisms are destroyed?
A.To emphasize how surprising it is that so many fossils exist.
B.To introduce a new geologic theory of fossil preservation.
C.To explain why the fossil record until now has remained incomplete.
D.To compare how fossils form on land and in water.
3.The word "terrestrial" in the passage (paragraph 1) is closest in meaning to
A.land.
B.protected.
C.alternative.
D.similar.
4.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage (paragraph 2)? Incorrect choices change the meaning in important ways or leave out essential information.
A.When snail or clam shells are left behind, they must be empty in order to remain durable and resist dissolution.
B.Although snail and clam shells are durable and resist dissolving, over time they slowly begin to change.
C.Although the soft parts of snails or clams dissolve quickly, their hard shells resist dissolution for a long time.
D.Empty snail or clam shells that are strong enough not to dissolve may stay in their original state for a long time.
5.Why does the author mention "aragonite" in the passage (paragraph 2)?
A.To emphasize that some fossils remain unaltered for millions of years.
B.To contrast fossil formation in organisms with soft tissue and in organisms with hard shells.
C.To explain that some marine organisms must undergo chemical changes in order to fossilize.
D.To explain why fossil shells are more likely to survive than are fossil skeletons.
6.The word "enhance" in the passage (paragraph 3) is closest in meaning to
A.control.
B.limit.
C.combine.
D.increase.
7.Which of the following best explains the process of permineralization mentioned in paragraph 3?
A.Water containing calcium carbonate circulates through a shell and deposits sediment.
B.Liquid containing chemicals hardens an already existing fossil structure.
C.Water passes through sediment surrounding a fossil and removes its chemical content.
D.A chemical substance enters a fossil and changes its shape.
8.The word "precise" in the passage (paragraph 4) is closest in meaning to
A.complex.
B.quick.
C.exact.
D.reliable.
9.Paragraph 5 suggests which of the following about the carbonization process?
A.It is completed soon after an organism dies.
B.It does not occur in hard-shell organisms.
C.It sometimes allows soft-tissued organisms to be preserved with all their parts.
D.It is a more precise process of preservation than is replacement.
10.The word "prospect" in the passage (paragraph 6) is closest in meaning to
A.completion.
B.variety.
C.possibility.
D.speed.
11.According to paragraph 7, how do environments containing oxygen affect fossil preservation?
A.They increase the probability that soft-tissued organisms will become fossils.
B.They lead to more bacteria production.
C.They slow the rate at which clay and silt are deposited.
D.They reduce the chance that animal remains will be preserved.
12.According to paragraph 7，all of the following assist in fossil preservation EXCEPT
A.the presence of calcite in an organism's skeleton.
B.the presence of large open areas along an ocean floor.
C.the deposition of a fossil in sticky substances such as sap or tar.
D.the rapid burial of an organism under layers of silt.
13. Look at the four squares [■] that indicate where the following sentence can be added to the passage. Where would the sentence best fit? Click on a square [■] to insert the sentence in the passage. But the evidence of past organic life is not limited to petrifaction. ■【A】Another type of fossilization, known as carbonization, occurs when soft tissues are preserved as thin films of carbon. ■【B】Leaves and tissue of soft-bodied organisms such as jellyfish or worms may accumulate, become buried and compressed, and lose their volatile constituents. ■【C】The carbon often remains behind as a blackened silhouette.■【D】
14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. The remains of ancient life are amazingly well preserved in the form of fossils.
A.Environmental characteristics like those present on ocean floors increase the likelihood that plant and animal fossils will occur.
B.Fossils are more likely to be preserved in shale deposits than in deposits of clay and silt.
C.The shells of organisms can be preserved by processes of chemical precipitation or mineral exchange.
D.Freezing enables the soft parts of organisms to survive longer than the hard parts.
E.Comparatively few fossils are found in the terrestrial deposits of streams and lakes.
F.Thin films of carbon may remain as an indication of soft tissue or actual tissue may be preserved if exposure to bacteria is limited.
托福 閱讀答案
1.agency代理，中介，作用，所以答案是force，選C。原句說(shuō)由于腐食動(dòng)物和細(xì)菌的侵襲，化學(xué)侵蝕和其他地質(zhì)什么的作用，使得保存的難度非常大。combination組合明顯不靠譜，problem是個(gè)負(fù)向詞，不靠譜，之前并列的都不是變化，change不對(duì)。
2.修辭目的題，修辭點(diǎn)所在句是一個(gè)例子，所以往前看，前一句說(shuō)fossil遭破壞的方式和fossil一樣多，后面就跟了很多破壞的方式，所以答案是A，闡釋為什么如此多破壞之下還有這么多化石存在。往后看也可以，下一句說(shuō)如果化石有骨架的話被保留的機(jī)會(huì)會(huì)大增，也就是一直都在說(shuō)化石存留下來(lái)的機(jī)會(huì)，所以A是正確答案。
3.terrestrial陸地的，陸生的，所以正確答案是A。原文說(shuō)盡管大部分的化石都是在海洋中找到的，但也有一些是在河湖中的什么沉積物當(dāng)中找到的，既然前文都說(shuō)了大部分是在海洋里找到的，肯定后面會(huì)說(shuō)是在陸地上找到的，所以答案是terrestrial，B/C/D都不靠譜。
4.原句的結(jié)構(gòu)是并列加條件，所以正確答案是D。A的must be empty原文沒(méi)說(shuō);B和C的關(guān)系都錯(cuò)誤;D說(shuō)的是shell會(huì)被剩下，如果足夠耐腐蝕，就能保存一段時(shí)間。
5.修辭目的題，先看例子所在 句子，說(shuō)很多海洋生物的骨骼包含calcite，沒(méi)有答案，往前看，前一句說(shuō)一億年前的沉積物中能發(fā)現(xiàn)骨骼不變的海生無(wú)脊椎動(dòng)物，與A靠譜，但A本身不是一個(gè)觀點(diǎn)，所以A不對(duì);B和D完全沒(méi)說(shuō)，不對(duì);強(qiáng)調(diào)的中心在例子所在句的下一句，說(shuō)arogonite的晶體形狀不同，相對(duì)不那么穩(wěn)定，會(huì)變成更穩(wěn)定的形式，所以答案是C，想穩(wěn)定的話必須再變。
6.enhance提升，提高，所以正確答案是D的increase。原文說(shuō)很多化學(xué)過(guò)程都能改變殼體的結(jié)構(gòu)并且怎么樣它們作為化石保留下來(lái)的機(jī)會(huì)，combine明顯不靠譜;limit和control意思相近，而且這兩個(gè)詞與increase意思相反，所以其他三個(gè)都不對(duì)。
7.以permineralization做關(guān)鍵詞定位至最后一句。說(shuō)將chemically precipitate的物質(zhì)加入precipitate的過(guò)程叫做permineralization，this指代前文，所以往前看，前面說(shuō)血管和神經(jīng)占據(jù)的空隙會(huì)被充填，骨頭和殼體會(huì)留下來(lái)，變得更堅(jiān)固，所以答案是B，變得更堅(jiān)硬。A的包含calcium不全面，而且原文的變硬也沒(méi)說(shuō);C的remove chemical content和D的change shape都沒(méi)說(shuō)。
8.precise精確的，所以C 的exact正確。原文說(shuō)replacement是一個(gè)非常什么樣的過(guò)程，殼體的紋飾，樹輪和骨架上的微細(xì)結(jié)構(gòu)都被記錄下來(lái)，B快和D可信完全不靠譜，細(xì)微結(jié)構(gòu)被記錄下來(lái)不見(jiàn)得復(fù)雜，所以complex也不對(duì)。
9.此段較短，完全可以快速掃完，當(dāng)然用排除法也比較好。A錯(cuò)，原文說(shuō)生命死后要經(jīng)過(guò)若干過(guò)程才會(huì)carbonization，所以A的soon明顯錯(cuò);B正確，原文明確指出carbonization發(fā)生在柔軟組織中，當(dāng)然也就不會(huì)發(fā)生在硬殼動(dòng)物身上;C的all their parts和D的比較原文都沒(méi)說(shuō)，都錯(cuò)。
10.prospect展望，前景，勘探，所以C 的possibility正確。原句說(shuō)盡管有硬殼提高了保存下來(lái)的什么，但軟體動(dòng)物也能偶爾被保存下來(lái)。根據(jù)讓步推出硬殼動(dòng)物應(yīng)該是容易保存下來(lái)，但跟保存下來(lái)的完整性和種類都無(wú)關(guān)，所以variety和completion都不對(duì)，speed完全不沾邊。
11.以oxygen做關(guān)鍵詞定位至第一句，說(shuō)如果快速埋藏，并且在缺氧環(huán)境下，化石保存的概率會(huì)增加，也就是說(shuō)氧的存在不利于化石的保存，所以正確答案是D，A與D剛好完全相反，所以A錯(cuò)，也說(shuō)明兩個(gè)相反的有一個(gè)對(duì);C完全沒(méi)說(shuō);B錯(cuò)，原文說(shuō)缺氧能減輕細(xì)菌的破壞作用，但并不意味著有氧細(xì)菌就會(huì)變多，所以B沒(méi)說(shuō)。
12.EXCEPT題，排除法，由于考全文，應(yīng)該關(guān)注各段開頭。A的skeleton和calcite做關(guān)鍵詞定位至第六段首句，正確，不選;B的ocean floor在原文中雖然有出現(xiàn)，但open areas沒(méi)有，所以B錯(cuò)，選;C的sap or tar做關(guān)鍵詞定位至第六段最后一句，正確，不選;D的rapid burial和layer of silt做關(guān)鍵詞定位至第七段第一句，正確，不選。
13.如果找名詞過(guò)渡，最容易找到的當(dāng)屬petrification，但遺憾的是，整段中既沒(méi)有petrification，也沒(méi)有 同義詞 替換，這段段首已經(jīng)開始說(shuō)carbonization，也就是說(shuō)petrification應(yīng)該是上一段或者下一段說(shuō)的，也就是A或者D正確，但待插入句說(shuō)不僅限于，也就是前面已經(jīng)說(shuō)過(guò)petrification了，所以A對(duì)D錯(cuò)。
14.Environmental選項(xiàng)對(duì)應(yīng)原文首段第三句，A正確。Fossils選項(xiàng)的比較原文沒(méi)說(shuō)，B不選。The shells選項(xiàng)對(duì)應(yīng)原文第三段最后一句和第四段開頭句，C正確。Freezing選項(xiàng)在原文第六段結(jié)尾捎帶提了一下，但沒(méi)說(shuō)比較，D不選。Comparatively選項(xiàng)與原文第一段倒數(shù)第二句說(shuō)反，E不選。The films選項(xiàng)對(duì)應(yīng)原文第五段和第七段開頭，F(xiàn)正確。
托福閱讀譯文
【1】如果想想生物在死之后被完全摧毀的種.種方式，能夠這樣頻繁出現(xiàn)化石是一件很令人驚訝的事。食腐動(dòng)物和細(xì)菌的破壞、化學(xué)性腐爛、腐蝕以及 其它 地質(zhì)因素都會(huì)非常不利于保存。不過(guò)，如果生物體碰巧具有礦化的骨骼并且死于可以迅速被沉積物掩埋的地方，擺脫被完全摧毀的幾率便會(huì)大大增加。海底通常就具有上述的兩方面條件，這里生活著很多帶殼的無(wú)脊椎動(dòng)物(沒(méi)有脊椎的動(dòng)物)，不斷累積的似雨的沉積顆粒會(huì)把它們掩埋起來(lái)。雖然多數(shù)的化石是在海洋沉積巖中發(fā)現(xiàn)的，但是在溪流和湖泊留下的陸相沉積物中也發(fā)現(xiàn)過(guò)。有時(shí)，浸入焦油和流沙、陷入冰或熔巖流或被急速降落的火山灰吞噬的動(dòng)植物得以保存下來(lái)?！?】術(shù)語(yǔ)“化石”常常意味著石化，字面意思就是變成了石頭。生物體死后，軟組織一般會(huì)被食腐動(dòng)物和細(xì)菌吃掉?？赡軙?huì)留下蝸牛或蛤蜊空殼，如果空殼足夠堅(jiān)固并且能抵御分解，就有可能在很長(zhǎng)一段時(shí)間內(nèi)基本上保持原樣。事實(shí)上，我們現(xiàn)在所知的在沉積物中發(fā)現(xiàn)的海洋無(wú)脊椎動(dòng)物保存良好的殼已超過(guò)了1億年之久。不過(guò)，很多海洋生物的骨骼是由稱為霰石的各式碳酸鈣礦物質(zhì)組成的。雖然霰石與我們更為熟悉的礦物方解石具有同樣的組成，但是它的晶型不同，相對(duì)不穩(wěn)定，最終會(huì)變成更穩(wěn)定的方解石。【3】很多其他過(guò)程也許會(huì)改變哈喇殼或蝸牛殼并且增加它被保存下來(lái)的幾率。含有溶解的二氧化硅、碳酸鈣或鐵的水可能會(huì)在封閉的沉積物中流動(dòng)，并沉積到諸如骨髓腔和骨頭管道內(nèi)，這些骨頭管道曾經(jīng)由血管和神經(jīng)占據(jù)。這種情況下，骨和殼的原始組成沒(méi)有改變，但是形成的化石更堅(jiān)硬并且更持久。這種在孔隙中填充化學(xué)沉積物的過(guò)程就叫做“完全礦化”?！?】石化還可能同時(shí)涉及死亡的動(dòng)植物的原有物質(zhì)與不同組成的礦物質(zhì)的交換作用。該過(guò)程叫做“置換作用”，因?yàn)槿芤喝芙饬嗽嘉镔|(zhì)并將其置換成為等體積的新物質(zhì)。置換是一個(gè)讓人難以置信的精確過(guò)程，貝殼裝飾的細(xì)節(jié)、樹木的年輪以及骨骼的精細(xì)結(jié)構(gòu)都被精準(zhǔn)地保存下來(lái)。【5】另一種類型的石化，稱為“碳化”，當(dāng)軟組織以碳薄膜的形式保存時(shí)會(huì)發(fā)生碳化。樹葉和軟體動(dòng)物例如水母或蠕蟲的組織可能會(huì)堆積起來(lái)，被掩埋并被壓實(shí)，然后其中的揮發(fā)性成分會(huì)消失。碳通常以一種黑色輪廓的形式被保留下來(lái)?！?】雖然擁有堅(jiān)硬的部分的確會(huì)增加保存的可能性，但是具有軟組織和器官的生物偶爾也會(huì)被保存下來(lái)。在針葉樹以及某些其它的樹種的凝固樹脂中就發(fā)現(xiàn)了昆蟲甚至是很小的無(wú)脊椎動(dòng)物。對(duì)巖石薄片的X射線檢查有時(shí)會(huì)發(fā)現(xiàn)可怕的觸角輪廓、消化道和很多種海洋生物的視覺(jué)器官。凍土或石油滲漏時(shí)滲出的焦油中保存了包括皮膚、毛發(fā)和冰河時(shí)代猛犸象的內(nèi)臟在內(nèi)的軟組織?！?】如果生物體死于一個(gè)快速沉積和缺氧的環(huán)境，會(huì)有助于軟組織殘骸的保存。在這種條件下，細(xì)菌的破壞性影響會(huì)降低。德國(guó)始新世中期的麥塞爾頁(yè)巖(來(lái)自4800萬(wàn)年前)就是在這種環(huán)境下積累起來(lái)的。該頁(yè)巖在一個(gè)缺氧的湖泊里沉積，那里時(shí)有致命的氣體冒出并殺死動(dòng)物。動(dòng)物的殘骸在湖底聚集，然后被粘土和淤泥所覆蓋。在保存完好的麥塞爾化石中有帶閃亮外骨骼(硬質(zhì)外部覆蓋物)的昆蟲，皮膚和血管完好無(wú)損的青蛙，甚至是毛皮和軟組織都完整保存的小型哺乳動(dòng)物。
托福閱讀TPO20(試題+答案+譯文)第3篇:Fossil Preservation相關(guān) 文章 ：
TPO是我們常用的托福?？脊ぞ?，對(duì)我們的備考很有價(jià)值，下面我給大家?guī)?lái)托福閱讀TPO16(試題+答案+譯文)第1篇:Trade and the Ancient Middle East。
托福閱讀原文
Trade was the mainstay of the urban economy in the Middle East, as caravans negotiated the surrounding desert, restricted only by access to water and by mountain ranges. This has been so since ancient times, partly due to the geology of the area, which is mostly limestone and sandstone, with few deposits of metallic ore and other useful materials Ancient demands for obsidian (a black volcanic rock useful for making mirrors and tools) led to trade with Armenia to the north, while jade for cutting tools was brought from Turkistan, and the precious stone lapis lazuli was imported from Afghanistan. One can trace such expeditions back to ancient Sumeria, the earliest known Middle Eastern civilization. Records show merchant caravans and trading posts set up by the Sumerians in the surrounding mountains and deserts of Persia and Arabia, where they traded grain for raw materials, such as timber and stones, as well as for metals and gems.
Reliance on trade had several important consequences. Production was generally in the hands of skilled individual artisans doing piecework under the tutelage of a master who was also the shop owner. In these shops differences of rank were blurred as artisans and masters labored side by side in the same modest establishment, were usually members of the same guild and religious sect, lived in the same neighborhoods, and often had assumed (or real) kinship relationships. The worker was bound to the master by a mutual contract that either one could repudiate, and the relationship was conceptualized as one of partnership.
This mode of craft production favored the growth of self-governing and ideologically egalitarian craft guilds everywhere in the Middle Eastern city. These were essentially professional associations that provided for the mutual aid and protection of their members, and allowed for the maintenance of professional standards. The growth of independent guilds was furthered by the fact that surplus was not a result of domestic craft production but resulted primarily from international trading; the government left working people to govern themselves, much as shepherds of tribal confederacies were left alone by their leaders. In the multiplicity of small-scale local egalitarian or quasi-egalitarian organizations for fellowship, worship, and production that flourished in this laissez-faire environment, individuals could interact with one another within a community of harmony and ideological equality, following their own popularly elected leaders and governing themselves by shared consensus while minimizing distinctions of wealth and power.
The mercantile economy was also characterized by a peculiar moral stance that is typical of people who live by trade—an attitude that is individualistic, calculating, risk taking, and adaptive to circumstances. As among tribespeople, personal relationships and a careful weighing of character have always been crucial in a mercantile economy with little regulation, where one's word is one's bond and where informal ties of trust cement together an international trade network. Nor have merchants and artisans ever had much tolerance for aristocratic professions of moral superiority, favoring instead an egalitarian ethic of the open market, where steady hard work, the loyalty of one's fellows, and ntrepreneurial skill make all the difference. And, like the pastoralists, Middle Eastern merchants and artisans unhappy with their environment could simply pack up and leave for greener pastures—an act of self-assertion wholly impossible in most other civilizations throughout history.
Dependence on long-distance trade also meant that the great empires of the Middle East were built both literally and figuratively on shifting sand. The central state, though often very rich and very populous, was intrinsically fragile, since the development of new international trade routes could undermine the monetary base and erode state power, as occurred when European seafarers circumvented Middle Eastern merchants after Vasco da Gama's voyage around Africa in the late fifteenth century opened up a southern route. The ecology of the region also permitted armed predators to prowl the surrounding barrens, which were almost impossible for a state to control. Peripheral peoples therefore had a great advantage in their dealings with the center, making government authority insecure and anxious.
托福閱讀試題
1.According to paragraph 1, why has trade been so important throughout the history of the Middle East
A.The rare and valuable metals and stones found in Middle Eastern deserts have always been in high demand in surrounding areas.
B.Growing conditions throughout the Middle East are generally poor, forcing Middle Eastern people to depend on imported grain.
C.Many useful and decorative raw materials cannot be found naturally in the Middle East but are available from neighboring regions.
D.Frequent travel, due to limited water supplies in the Middle East, created many opportunities for trade with neighboring societies.
2.The word “repudiate” in the passage (paragraph 2) is closest in meaning to
A.respect
B.reject
C.review
D.revise
3.According to paragraph 2, how did Middle Eastern shop owners treat their workers?
A.Workers were ranked according to their skill level, with the most-experienced artisans becoming partial owners of the shop.
B.Shop owners treated different workers differently depending on how much the workers had in common with their masters.
C.Workers were bound to their masters by unbreakable contracts that strictly defined the terms of their partnership.
D.The shop owner worked alongside the workers and often considered them partner and members of the family.
4.The author includes the information that surplus was not a result of domestic craft production but resulted primarily from international trading (in passage 3) in order to
A.support the claim that the mode of production made possible by the craft guilds w very good for trade
B.contrast the economic base of the city government with that of the tribal confederacies
C.provide a reason why the government allowed the guilds to be self-controlled
D.suggest that the government was missing out on a valuable opportunity to tax the guilds
5.According to paragraph 3, all of the following are true of the Middle Eastern craft guilds EXCEPT:
A.The guilds were created to support workers and to uphold principles of high-quality craft production.
B.Each guild was very large and included members from a broad geographic area.
C.The leaders of the guilds were chosen by popular vote.
D.All guild members were treated as equals.
6.The word “consensus” in the passage (paragraph 3) is closest in meaning to
A.authority
B.responsibility
C.custom
D.agreement
7.According to paragraph 4, which of the following was NOT necessary for success in themercantile economy?
A.Good business sense
B.Reliable associates
C.Family wealth
D.Constant effort
8.Which of the sentences below best expresses the essential information in the highlighted sentence in paragraph 4? Incorrect choices change the meaning in important ways or leave out essential information.
A.Tribes people were comfortable forming personal relationships with merchants, who, like them, were bound by their promises to one another.
B.Because trade was not formally regulated, merchants were careful about whom they trusted and often conducted business with people they knew personally.
C.While trade among merchants relied somewhat on regulation, among tribes people trade was based on personal relationships and careful character evaluation.
D.Because tribes people were bound only by their promises to one another, personal relationships were formed only after careful weighing of character.
9.The word “ethic” in the passage (paragraph 4) is closest in meaning to
A.set of moral principles
B.division of labor
C.economic system
D.test of character
10.According to paragraph 4, what choice did Middle Eastern merchants and artisans have that many other people have not had?
A.If they were unhappy in the mercantile environment, they could draw on personal connections to find a different kind of work.
B.They were allowed to assert their opinions without having to listen to aristocratic professions of moral superiority.
C.Following the example of the pastoralists, they could demand, and receive, better working conditions.
D.If they didn't like their environment, they could move somewhere else.
11.The word “intrinsically” in the passage (paragraph 5) is closest in meaning to
A.fundamentally
B.surprisingly
C.consequently
D.particularly
12.In paragraph 5, why does the author mention the new trade route opened up by Vasco da Gama's fifteenth century voyage around Africa?
A.To provide evidence that European seafarers took every opportunity to bypass Middle Eastern merchants
B.To present an instance in which Middle Eastern states lost money and power because of their reliance on long-distance trade
C.To argue this new route became necessary when European seafarers wanted to avoid Middle Eastern states whose central power had begun to erode
D.To explain how da Gama helped European traders avoid the dangerous predators prowling the areas surrounding Middle Eastern cities
13. Look at the four squares [■] that indicate where the following sentence could be added to the passage. Where would the sentence best fit? For one thing, it created a demand for finished goods to be sold both locally and abroad.
Paragraph2: Reliance on trade had several important consequences. ■【A】Production was generally in the hands of skilled individual artisans doing piecework under the tutelage of a master who was also the shop owner. ■【B】In these shops differences of rank were blurred as artisans and masters labored side by side in the same modest establishment, were usually members of the same guild and religious sect, lived in the same neighborhoods, and often had assumed (or real) kinship relationships. ■【C】The worker was bound to the master by a mutual contract that either one could repudiate, and the relationship was conceptualized as one of partnership. ■【D】
14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
Since ancient times. reliance on trade has shaped the culture and organizational structure of Middle Eastern societies.
A.Persian and Arabian merchants traveled great distances to sell their finished goods at the marketplaces of ancient Sumeria.
B.Revenue from trade was unevenly distributed, causing Middle Eastern societies to be characterized by growing distinctions in wealth and power.
C.Qualities that were valued in the mercantile economy included individualism, hard work, loyalty, and the willingness to take risks.
D.As production increased, centralized control over production also increased, leading in turn to more-centralized control over fellowship and worship.
E.Crafts were produced by skilled artisans working in close, egalitarian relationships with their masters and other fellow guild members.
F.The stability of Middle Eastern governments was threatened by their lack of control over international trade patterns and over their own peripheral territories.
托福 閱讀答案
1.問(wèn)trade為什么主要，這段第一句就說(shuō)是mainstay，第二句就給出了原因，說(shuō)他們沒(méi)有這個(gè)沒(méi)有那個(gè)，所以答案是C。A說(shuō)中東有material，明顯與原文說(shuō)反;B的中東很窮和D的frequent travel原文都沒(méi)說(shuō)。
2.repudiate與……斷絕關(guān)系，駁斥，所以reject正確。原句說(shuō)師徒之間是一種契約關(guān)系，這個(gè)契約任意一方都可以怎么樣，下一句又說(shuō)是一種伙伴關(guān)系，也就是沒(méi)有強(qiáng)制性，所以答案是任何一方都可以撕毀，所以答案是reject。respect和review都不靠譜;revise單純的改變也不是作者的意思。
3.以shop owners做關(guān)鍵詞定位至第二句，但第二句沒(méi)有回答問(wèn)題，所以往后看，后一句說(shuō)老板和工人之間的界限被blur模糊了，而且他們同吃同住一起工作，所以答案是D。A的workers rank原文沒(méi)說(shuō);B說(shuō)對(duì)不同工人態(tài)度不同，與原文相反;C的unbreakable contract與最后一句相反。
4.修辭目的題，先看修辭點(diǎn)所在 句子，只是一個(gè)例子，放棄;往前看，說(shuō)有行業(yè)協(xié)會(huì)互助互惠，但這明顯也還是一個(gè)例子，所以看本段中心句，說(shuō)這種生產(chǎn)方式傾向于促進(jìn)自律平等的同業(yè)協(xié)會(huì)的發(fā)展，所以答案是C。
5.EXCEPT題，排除法。A的support workers和uphold principles做關(guān)鍵詞定位至第二句，原文的mutual aid and protection等于support workers，maintaneance of professional standards等于uphold principles，A正確，不選;B的geographic area原文沒(méi)有對(duì)應(yīng)點(diǎn)，錯(cuò)，選;C的vote做關(guān)鍵詞定位至最后一句，正確，不選;D的equals做關(guān)鍵詞定位至最后一句，正確，不選。
6.consensus合約，同意，協(xié)定，所以D的agreement正確。原句說(shuō)人與人之間的關(guān)系非常和諧，他們聽他們領(lǐng)導(dǎo)的話，通過(guò)什么實(shí)現(xiàn)自律并盡量減小貧富差距，減小差距就是為了求得某種一致，所以答案是agreement。A權(quán)威，B責(zé)任，C習(xí)慣，都不靠譜。
7.EXCEPT題，排除法。A與倒數(shù)第二句的entrepreneurial skill同義替換，正確，不選;B與倒數(shù)第二句的loyalty of one’s fellow同義替換，正確，不選;C在原文中無(wú)對(duì)應(yīng)點(diǎn)，錯(cuò)，選;D與倒數(shù)第二句的steady hard work同義替換，正確，不選。
8.原句的結(jié)構(gòu)是在什么什么人當(dāng)中，什么和什么很重要，在什么什么環(huán)境下。所以B正確。A混淆原文概念，原文說(shuō)在當(dāng)時(shí)的環(huán)境下只能靠promise形成商業(yè)網(wǎng)絡(luò)，人們和認(rèn)識(shí)的人做生意，不是人們靠promise做生意;C錯(cuò)，原文說(shuō)沒(méi)有regulation，C說(shuō)反;D錯(cuò)，因?yàn)閛nly原文從來(lái)沒(méi)說(shuō)過(guò)。
9.ethic道德規(guī)范，倫理，所以A正確。原文說(shuō)商人和工匠們不能忍受moral superiority，更喜歡open market的什么，既然不喜歡moral superiority，那么他們喜歡的東西也應(yīng)該跟道德有關(guān)，所以答案是A，而B勞力分工C經(jīng)濟(jì)體系和D性格測(cè)試完全不靠譜。
10.以many other people做關(guān)鍵詞定位至最后一句，說(shuō)如果不滿意當(dāng)?shù)氐纳虡I(yè)環(huán)境，中東商人會(huì)像游牧民族一樣遷移到其他地方，這是其他人做不到的，所以答案是D。
11.intrinsically本質(zhì)的，內(nèi)部的，固有的，所以答案A正確。原句說(shuō)盡管中部的國(guó)家很富裕而且人口稠密，但他們是怎么樣脆弱的，由于新的國(guó)際貿(mào)易路線可以決定金融資本所在的地方，并且能夠侵蝕國(guó)家的力量，都能侵蝕了，所以應(yīng)該是脆弱的，但前文又說(shuō)人口密集并且富裕，所以這些都是表象，所以答案是A的fundamentallly基礎(chǔ);B吃驚C結(jié)果D特別都沒(méi)反應(yīng)這種內(nèi)外的差別，所以都不對(duì)。
12.修辭目的題，先把本句讀清楚，說(shuō)新的國(guó)際貿(mào)易路線可以決定金融資本所在的地方，并且能夠侵蝕國(guó)家的力量，接著就說(shuō)就像達(dá)伽馬發(fā)現(xiàn)了新航路之后歐洲人繞過(guò)了中東，所以說(shuō)達(dá)伽馬的事兒是為了證明航線的發(fā)現(xiàn)能夠削弱國(guó)家的力量，所以答案是B。
13.兩個(gè)過(guò)渡點(diǎn)，連詞for one thing和名詞finished goods，既然是for one thing，就應(yīng)該放在比較靠前的位置上，所以A或者B有可能，而放在A正好對(duì)應(yīng)之前的several important consequences;而且finished goods與原文當(dāng)中的production對(duì)應(yīng)，所以A正確。
14.Persian選項(xiàng)是原文第一段中的一個(gè)細(xì)節(jié)，不選;Revenue選項(xiàng)與原文第三段最后一句說(shuō)反，是貧富差距縮小，不是擴(kuò)大，不選;Qualities選項(xiàng)對(duì)應(yīng)第四段，正確;As選項(xiàng)與原文第三段第一句相反，不選;Crafts選項(xiàng)對(duì)應(yīng)原文第二段和第三段的最后一句，正確;The stability選項(xiàng)對(duì)應(yīng)原文第五段第一句，正確。
托福閱讀譯文
自從中東地區(qū)的商旅們成功跨越周圍的戈壁，只有水路和山巒還是障礙時(shí)，貿(mào)易就成為了中東地區(qū)城市經(jīng)濟(jì)的主要支柱。這種情況(貿(mào)易是主要支柱)從古至今都是如此，一部分原因是中東地區(qū)的地質(zhì)環(huán)境——多為沙石和石灰?guī)r，金屬礦藏和 其它 有用材料很少。古代對(duì)黑曜石(一種火山巖，可以用來(lái)制作鏡子和工具)的需求引發(fā)了(中東地區(qū))與北方的亞美尼亞之間的貿(mào)易;用作切削工具的玉石從土耳其斯坦購(gòu)買;而稀有貴重的琉璃青金石是從阿富汗地區(qū)進(jìn)口。探險(xiǎn)活動(dòng)最早可以追溯至古蘇美爾——已知最早的中東文明。記錄顯示商隊(duì)和貿(mào)易站由古蘇美爾人在周圍山區(qū)及古波斯和阿拉伯的沙漠地區(qū)建立。
過(guò)于依賴貿(mào)易造成了一些重大影響。生產(chǎn)工作一般在師傅也是店主的監(jiān)視下，由熟練的工匠計(jì)件完成。在這些店鋪中，階級(jí)差異并不明顯，因?yàn)楣そ澈偷曛魍谝粋€(gè)相對(duì)舒適的環(huán)境中共事，通常有著相同的宗教信仰，而且又是街坊鄰里，彼此之間還很有可能(沒(méi)準(zhǔn)真的)是親戚關(guān)系。工人和店主雙方具有勞務(wù)關(guān)系，任一方都有權(quán)終止，這是合作關(guān)系中的一種。
這種生產(chǎn)模式有助于自主管理制度的發(fā)展，在中東城市里意識(shí)形態(tài)上秉持人人平等的手工行會(huì)比比皆是。他們實(shí)質(zhì)上是專門提供互助且保護(hù)組織成員的協(xié)會(huì)組織，同時(shí)注重維持行業(yè)標(biāo)準(zhǔn)。獨(dú)立行會(huì)不斷增加，是因?yàn)槭Ｓ鄡r(jià)值的產(chǎn)生并非由于國(guó)內(nèi)生產(chǎn)，而是主要來(lái)自于國(guó)際間的貿(mào)易活動(dòng)。政府允許勞動(dòng)人民自主管理，這和部落首領(lǐng)讓牧羊者們離群索居一樣。在當(dāng)?shù)兀瑘F(tuán)體、信仰以及生產(chǎn)方面的小型平等主義團(tuán)體或類似平等主義的組織在這種自由放任的環(huán)境里遍地開花，和諧平等的團(tuán)體中，成員之間相互影響，追隨著他們自己選舉的領(lǐng)導(dǎo)人，在縮小財(cái)富和權(quán)力差距的同時(shí)通過(guò)分享意見(jiàn)進(jìn)行自我管理。
商品經(jīng)濟(jì)也通過(guò)靠貿(mào)易為生的商人所秉持的特定道德立場(chǎng)表現(xiàn)出來(lái)。他們具有獨(dú)立自主、精于計(jì)算、敢于冒險(xiǎn)和隨遇而安的優(yōu)秀品質(zhì)。在部落成員之間，人際關(guān)系和謹(jǐn)言慎行的品質(zhì)在監(jiān)管不嚴(yán)的商品經(jīng)濟(jì)中至關(guān)重要,商品經(jīng)濟(jì)里人們出口成契，誠(chéng)信基礎(chǔ)上的非正式聯(lián)系形成了一個(gè)國(guó)際貿(mào)易網(wǎng)絡(luò)。從沒(méi)有商人和工匠對(duì)貴族職業(yè)的道德優(yōu)越感如此寬容，這很好地促進(jìn)了開放市場(chǎng)中的平等主義，人們辛勤工作，忠誠(chéng)跟隨，具備企業(yè)家精神非常重要。而且，這和畜牧文明類似，中東的商人和工匠們?nèi)魧?duì)自己所處的環(huán)境不滿意，簡(jiǎn)單收拾一下就可遷移到一個(gè)更加豐茂的牧場(chǎng)——縱觀歷史，如此隨性而為的行為在其他多數(shù)文明中是無(wú)法想象的。
對(duì)遠(yuǎn)距離貿(mào)易的依賴也意味著偉大的中東帝國(guó)得以建立在這片飄忽不定卻又無(wú)比真實(shí)的沙土之中。帝國(guó)中部盡管非常富足繁盛，但本質(zhì)上脆弱不堪，因?yàn)樾碌膰?guó)際貿(mào)易線路的出現(xiàn)會(huì)動(dòng)搖經(jīng)濟(jì)基礎(chǔ)并腐蝕國(guó)家權(quán)力。就在15世紀(jì)晚期達(dá)伽馬繞過(guò)非洲開辟南部航線以后，歐洲的水手們便繞過(guò)中東商人改走南部航線了。該地區(qū)的生態(tài)環(huán)境也允許武裝“捕食者”在周圍的荒漠潛行，幾乎很難被帝國(guó)控制。外圍的人借此得到一個(gè)應(yīng)對(duì)中央帝國(guó)的絕好機(jī)會(huì)，這讓政府惴惴不安。
蘇美爾人(也譯作蘇默)，是歷史上兩河流域(底格里斯河和幼發(fā)拉底河中下游)早期的定居民族，他們所建立的蘇美爾文明是整個(gè)美索不達(dá)米亞文明中最早，同時(shí)也是全世界最早產(chǎn)生的文明。
托福閱讀TPO16(試題+答案+譯文)第1篇:Trade and the Ancient Middle East相關(guān) 文章 ：
托福TPO作為大家托福備考的?？脊ぞ?，它的題目對(duì)我們有很大的參考價(jià)值，為了幫助大家備考，下面我給大家?guī)?lái)托福TPO2Part2閱讀原文及參考答案，望喜歡。
? ? ?托福TPO2Part2閱讀原文
The Origins Of Cetaceans
It should be obvious that cetaceans-whales, porpoises, and dolphins-are mammals. They breathe through lungs, not through gills, and give birth to live young. Their streamlined bodies, the absence of hind legs, and the presence of a fluke1 and blowhole2 cannot disguise their affinities with land dwelling mammals. However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and walruses, whose limbs are functional both on land and at sea), it is not easy to envision what the first whales looked like. Extinct but already fully marine cetaceans are known from the fossil record. How was the gap between a walking mammal and a swimming whale bridged? Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans.
Very exciting discoveries have finally allowed scientists to reconstruct the most likely origins of cetaceans. In 1979, a team looking for fossils in northern Pakistan found what proved to be the oldest fossil whale. The fossil was officially named Pakicetus in honor of the country where the discovery was made. Pakicetus was found embedded in rocks formed from river deposits that were 52 million years old. The river that formed these deposits was actually not far from an ancient ocean known as the Tethys Sea.
The fossil consists of a complete skull of an archaeocyte, an extinct group of ancestors of modern cetaceans. Although limited to a skull, the Pakicetus fossil provides precious details on the origins of cetaceans. The skull is cetacean-like but its jawbones lack the enlarged space that is filled with fat or oil and used for receiving underwater sound in modern whales. Pakicetus probably detected sound through the ear opening as in land mammals. The skull also lacks a blowhole, another cetacean adaptation for diving. Other features, however, show experts that Pakicetus is a transitional form between a group of extinct flesh-eating mammals, the mesonychids, and cetaceans. It has been suggested that Pakicetus fed on fish in shallow water and was not yet adapted for life in the open ocean. It probably bred and gave birth on land.
Another major discovery was made in Egypt in 1989. Several skeletons of another early whale, Basilosaurus, were found in sediments left by the Tethys Sea and now exposed in the Sahara desert. This whale lived around 40 million years ago, 12 million years after Pakicetus. Many incomplete skeletons were found but they included, for the first time in an archaeocyte, a complete hind leg that features a foot with three tiny toes. Such legs would have been far too small to have supported the 50-foot-long Basilosaurus on land. Basilosaurus was undoubtedly a fully marine whale with possibly nonfunctional, or vestigial, hind legs.
An even more exciting find was reported in 1994, also from Pakistan. The now extinct whale Ambulocetus natans ("the walking whale that swam") lived in the Tethys Sea 49 million years ago. It lived around 3 million years after Pakicetus but 9 million before Basilosaurus. The fossil luckily includes a good portion of the hind legs. The legs were strong and ended in long feet very much like those of a modern pinniped. The legs were certainly functional both on land and at sea. The whale retained a tail and lacked a fluke, the major means of locomotion in modern cetaceans. The structure of the backbone shows, however, that Ambulocetus swam like modern whales by moving the rear portion of its body up and down, even though a fluke was missing. The large hind legs were used for propulsion in water. On land, where it probably bred and gave birth, Ambulocetus may have moved around very much like a modern sea lion. It was undoubtedly a whale that linked life on land with life at sea
Fluke: the two parts that constitute the large triangular tail of a whale
1. "Blowhole: a hole in the top of the head used for breathing
Paragraph 1: It should be obvious that cetaceans-whales, porpoises, and dolphins-are mammals. They breathe through lungs, not through gills, and give birth to live young. Their streamlined bodies, the absence of hind legs, and the presence of a fluke3 and blowhole4 cannot disguise their affinities with land-dwelling mammals. However, unlike the cases of sea otters and pinnipeds (seals, sea lions, and walruses, whose limbs are functional both on land and at sea), it is not easy to envision what the first whales looked like. Extinct but, already fully marine cetaceans are known from the fossil record. How was the gap between a walking mammal and a swimming whale bridged? Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans.
托福TPO2Part2閱讀題目
Directions: Mark your answer by filling in the oval next to your choice.
1. In paragraph 1, what does the author say about the presence of a blowhole in cetaceans?
It clearly indicates that cetaceans are mammals.
It cannot conceal the fact that cetaceans are mammals.
It is the main difference between cetaceans and land-dwelling mammals.
It cannot yield clues about the origins of cetaceans.
2. Which of the following can be inferred from paragraph 1 about early sea otters?
It is not difficult to imagine what they looked like
There were great numbers of them.
They lived in the sea only.
They did not leave many fossil remains.
Paragraph 3: The fossil consists of a complete skull of an archaeocyte, an extinct group of ancestors of modern cetaceans. Although limited to a skull, the Pakicetus fossil provides precious details on the origins of cetaceans. The skull is cetacean-like but its jawbones lack the enlarged space that is filled with fat or oil and used for receiving underwater sound in modern whales. Pakicetus probably detected sound through the ear opening as in land mammals. The skull also lacks a blowhole, another cetacean adaptation for diving. Other features, however, show experts that Pakicetus is a transitional form between a group of extinct flesh-eating mammals, the mesonychids, and cetaceans. It has been suggested that Pakicetus fed on fish in shallow water and was not yet adapted for life in the open ocean. It probably bred and gave birth on land.
3. The word precious in the passage is closest in meaning to
Exact
Scarce
Valuable
Initial
4. Pakicetus and modern cetaceans have similar
Hearing structures
Adaptations for diving
Skull shapes
Breeding locations
5. The word it in the passage refers to
Pakicetus
Fish
Life
ocean
Paragraph 4: Another major discovery was made in Egypt in 1989. Several skeletons of another early whale, Basilosaurus, were found in sediments left by the Tethys Sea and now exposed in the Sahara desert. This whale lived around 40 million years ago, 12 million years after Pakicetus. Many incomplete skeletons were found but they included, for the first time in an archaeocyte, a complete hind leg that features a foot with three tiny toes. Such legs would have been far too small to have supported the 50-foot-long Basilosaurus on land. Basilosaurus was undoubtedly a fully marine whale with possibly nonfunctional, or vestigial, hind legs.
6. The word exposed in the passage is closest in meaning to
Explained
Visible
Identified
Located
7. The hind leg of Basilosaurus was a significant find because it showed that Basilosaurus
Lived later than Ambulocetus natans
Lived at the same time as Pakicetus
Was able to swim well
Could not have walked on land
8. It can be inferred that Basilosaurus bred and gave birth in which of the following locations
On land
Both on land and at sea
In shallow water
In a marine environment
Paragraph 5: An even more exciting find was reported in 1994, also from Pakistan. The now extinct whale Ambulocetus natans ("the walking whale that swam") lived in the Tethys Sea 49 million years ago. It lived around 3 million years after Pakicetus but 9 million before Basilosaurus. The fossil luckily includes a good portion of the hind legs. The legs were strong and ended in long feet very much like those of a modern pinniped. The legs were certainly functional both on land and at sea. The whale retained a tail and lacked a fluke, the major means of locomotion in modern cetaceans. The structure of the backbone shows, however, that Ambulocetus swam like modern whales by moving the rear portion of its body up and down, even though a fluke was missing. The large hind legs were used for propulsion in water. On land, where it probably bred and gave birth, Ambulocetus may have moved around very much like a modern sea lion. It was undoubtedly a whale that linked life on land with life at sea
9. Why does the author use the word luckily in mentioning that the Ambulocetus natans fossil included hind legs?
Fossil legs of early whales are a rare find.
The legs provided important information about the evolution of cetaceans.
The discovery allowed scientists to reconstruct a complete skeleton of the whale.
Until that time, only the front legs of early whales had been discovered.
10. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage?
Incorrect choices change the meaning in important ways or leave out essential information.
Even though Ambulocetus swam by moving its body up and down, it did not have a backbone.
The backbone of Ambulocetus, which allowed it to swim, provides evidence of its missing fluke.
Although Ambulocetus had no fluke, its backbone structure shows that it swam like modern whales.
By moving the rear parts of their bodies up and down, modern whales swim in a different way from the way Ambulocetus swam.
11. The word propulsion in the passage is closest in meaning to
Staying afloat
Changing direction
Decreasing weight
Moving forward
Paragraph 1: Extinct but already fully marine cetaceans are known from the fossil record. ■How was the gap between a walking mammal and a swimming whale bridged? ■Missing until recently were fossils clearly intermediate, or transitional, between land mammals and cetaceans.■Very exciting discoveries have finally allowed scientists to reconstruct the most likely origins of cetaceans. ■In 1979, a team looking for fossils in northern Pakistan found what proved to be the oldest fossil whale.
12. Look at the four squares [■] that indicate where the following sentence can be added to the passage.
This is a question that has puzzled scientists for ages.
Where would the sentence best fit?
13-14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
This passage discusses fossils that help to explain the likely origins of cetaceans-whales, porpoises, and dolphins.
●
●
●
Answer Choices
1. Recent discoveries of fossils have helped to show the link between land mammals and cetaceans.
2. The discovery of Ambulocetus natans provided evidence for a whale that lived both on land and at sea.
3. The skeleton of Basilosaurus was found in what had been the Tethys Sea, an area rich in fossil evidence.
4. Pakicetus is the oldest fossil whale yet to be found.
5. Fossils thought to be transitional forms between walking mammals and swimming whales were found.
6. Ambulocetus' hind legs were used for propulsion in the water
托福TPO2Part2 閱讀答案
參考答案：
1、2
2、1
3、3
4、3
5、1
6、2
7、4
8、4
9、2
10. 3
11. 4
12. 2
13-14. 1 2 5
托福TPO2Part2閱讀原文翻譯
沙漠已經(jīng)占據(jù)了地球表面積約四分之一，而且最近幾十年正以驚人的速度擴(kuò)張。沙漠化是指類似沙漠的環(huán)境漫延到原本并非沙漠的區(qū)域。據(jù)估計(jì)，地球表面另外四分之一的地方正面臨沙漠化威脅。
沙漠化主要通過(guò)以下過(guò)程實(shí)現(xiàn)：首先自然植被不斷減少，隨后風(fēng)力和 雨水 加速了土壤的腐蝕。有的時(shí)候松散的土壤全部被風(fēng)刮走，留下石質(zhì)化的表層; 其它 情況下細(xì)小的沙?？赡軙?huì)被吹走，而正常沙粒大小的砂子不斷堆積，從而形成移動(dòng)的沙丘或者沙脊。
即便是在保留了土壤表層的區(qū)域，植被減少也已成為土壤大量吸取地下水的能力下降的典型因素。雨水對(duì)松散土壤的沖擊會(huì)把細(xì)小的粘土顆粒沖到土壤空隙中，封閉了土壤并降低土地表層水的滲透率。地表對(duì)水的吸收急劇減少，大量水資源流失，因此土壤的腐蝕率也隨即增加。地表吸收水分的能力進(jìn)一步弱化使得土壤越發(fā)干燥，導(dǎo)致植被的進(jìn)一步流失，于是便形成了土壤沙漠化的惡性循環(huán)。
在一些地方，沙漠面積的擴(kuò)大很大程度上歸因于干燥的氣候條件。在過(guò)去的幾千年里，不斷增加的溫室效應(yīng)使得一些地方干旱問(wèn)題愈發(fā)嚴(yán)重。倘若空氣污染帶來(lái)的溫室效應(yīng)繼續(xù)惡化，沙漠化進(jìn)程會(huì)在未來(lái)數(shù)十年內(nèi)加速實(shí)現(xiàn)。
然而，可以肯定的是，大部分地區(qū)沙漠化主要都是由于人類活動(dòng)造成，而非自然條件導(dǎo)致。沙漠邊緣的半干旱土地所處的生態(tài)平衡環(huán)境非常脆弱，環(huán)境壓力持續(xù)增加，而這些半干旱區(qū)域適應(yīng)環(huán)境壓力的能力極其有限。人口數(shù)量的增加使得人們不斷向土地施壓，依其提供食物和燃料。在濕潤(rùn)的季節(jié)里，土地興許能夠應(yīng)付這些壓力。但是在干旱的季節(jié)里，在沙漠周邊的土地上，存在著這樣一個(gè)十分普遍的現(xiàn)象：人類對(duì)土地施加的壓力遠(yuǎn)遠(yuǎn)超過(guò)了土地自身減壓的能力，因此最終形成了沙漠。
導(dǎo)致沙漠化的主要因素有四個(gè)：過(guò)度 種植，過(guò)度放牧，過(guò)分砍伐，過(guò)度灌溉。由于人口密度增加，人們對(duì)糧食作物的種植已經(jīng)擴(kuò)展到日益干燥的區(qū)域進(jìn)行。這些區(qū)域很有可能經(jīng)常會(huì)發(fā)生干旱，所以農(nóng)作物種植失敗是很正常的事情。大多數(shù)農(nóng)作物的種植需要事先移除天然植被，而農(nóng)作物欠收后又會(huì)留下大面積荒地，非常容易被風(fēng)力和雨水侵蝕。
在半干旱地區(qū)，草坪是主要的天然植被，家畜 飼養(yǎng) 是當(dāng)?shù)氐囊豁?xiàng)主要經(jīng)濟(jì)活動(dòng)。在一個(gè)地區(qū)過(guò)量飼養(yǎng)家畜會(huì)導(dǎo)致植被覆蓋面積減少，土地被大量踐踏和碾碎。通常，隨之而來(lái)的就是土地硬化和加速侵蝕。
在很多國(guó)家木材是用來(lái)做飯和加熱的最主要燃料。人口增加帶來(lái)的壓力促使人們大量砍伐木材，導(dǎo)致許多城市和鄉(xiāng)村周圍大面積樹木和灌木減少。同時(shí)人們大量使用烘干的動(dòng)物排泄物作為替代燃料同樣對(duì)土壤不利，因?yàn)檫@些珍貴的土壤成分調(diào)節(jié)劑和植物營(yíng)養(yǎng)資源將不會(huì)再回歸至土壤當(dāng)中。
造成土地沙漠化的最后一個(gè)主要人為因素在于人類過(guò)度灌溉導(dǎo)致土壤的鹽堿化。灌溉多余的水滲透到地下水位。假如沒(méi)有排水系統(tǒng)的存在，那么地下水位上升，把溶解的鹽分帶到土壤表面。水分蒸發(fā)后，鹽分留在了表面，形成白色的地殼層，這一地殼層阻止了空氣和水接觸地底下的土壤。
沙漠化問(wèn)題異常嚴(yán)重，這是因?yàn)橛衼鋸V闊的地區(qū)和數(shù)量龐大的人群都受到了沙漠化的影響，而且要想逆轉(zhuǎn)沙漠化的進(jìn)程甚至減緩沙漠化的速度都面臨著巨大的困難。一旦土壤被侵蝕，需要再經(jīng)過(guò)幾百到上千年的時(shí)間才會(huì)產(chǎn)生新的土壤。那些大量土壤仍保存完好的地方，亟需一個(gè)嚴(yán)謹(jǐn)而有力的保護(hù)政策和植被覆蓋計(jì)劃來(lái)保護(hù)現(xiàn)有土地。
托福TPO2Part2閱讀原文及參考答案相關(guān) 文章 ：
1. tpo2閱讀真題 part2
2. 托福閱讀理解需要讀全文嗎
3. 托福獨(dú)立寫作萬(wàn)能例子有哪些
4. 托福聽力16-27分,我是這么做的
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9. 托福口語(yǔ)task4模板及答題策略
10. tpo2閱讀真題 part2
托福TPO作為托福的?？脊ぞ撸念}目對(duì)于我們備考托福很有參考價(jià)值，為了幫助大家備考，下面我給大家整理了托福TPO3閱讀真題原文Part3，望喜歡！
? ? ?托福TPO3閱讀真題原文Part3
The Long-Term Stability of Ecosystems
Plant communities assemble themselves flexibly, and their particular structure depends on the specific history of the area. Ecologists use the term "succession" to refer to the changes that happen in plant communities and ecosystems over time. The first community in a succession is called a pioneer community, while the long-lived community at the end of succession is called a climax community. Pioneer and successional plant communities are said to change over periods from 1 to 500 years. These changes-in plant numbers and the mix of species-are cumulative. Climax communities themselves change but over periods of time greater than about 500 years.
An ecologist who studies a pond today may well find it relatively unchanged in a year's time. Individual fish may be replaced, but the number of fish will tend to be the same from one year to the next. We can say that the properties of an ecosystem are more stable than the individual organisms that compose the ecosystem.
At one time, ecologists believed that species diversity made ecosystems stable. They believed that the greater the diversity the more stable the ecosystem. Support for this idea came from the observation that long-lasting climax communities usually have more complex food webs and more species diversity than pioneer communities. Ecologists concluded that the apparent stability of climax ecosystems depended on their complexity. To take an extreme example, farmlands dominated by a single crop are so unstable that one year of bad weather or the invasion of a single pest can destroy the entire crop. In contrast, a complex climax community, such as a temperate forest, will tolerate considerable damage from weather to pests.
The question of ecosystem stability is complicated, however. The first problem is that ecologists do not all agree what "stability" means. Stability can be defined as simply lack of change. In that case, the climax community would be considered the most stable, since, by definition, it changes the least over time. Alternatively, stability can be defined as the speed with which an ecosystem returns to a particular form following a major disturbance, such as a fire. This kind of stability is also called resilience. In that case, climax communities would be the most fragile and the least stable, since they can require hundreds of years to return to the climax state.
Even the kind of stability defined as simple lack of change is not always associated with maximum diversity. At least in temperate zones, maximum diversity is often found in mid-successional stages, not in the climax community. once a redwood forest matures, for example, the kinds of species and the number of individuals growing on the forest floor are reduced. In general, diversity, by itself, does not ensure stability. Mathematical models of ecosystems likewise suggest that diversity does not guarantee ecosystem stability-just the opposite, in fact. A more complicated system is, in general, more likely than a simple system to break down. A fifteen-speed racing bicycle is more likely to break down than a child's tricycle.
Ecologists are especially interested to know what factors contribute to the resilience of communities because climax communities all over the world are being severely damaged or destroyed by human activities. The destruction caused by the volcanic explosion of Mount St. Helens, in the northwestern United States, for example, pales in comparison to the destruction caused by humans. We need to know what aspects of a community are most important to the community's resistance to destruction, as well as its recovery.
Many ecologists now think that the relative long-term stability of climax communities comes not from diversity but from the "patchiness" of the environment, an environment that varies from place to place supports more kinds of organisms than an environment that is uniform. A local population that goes extinct is quickly replaced by immigrants from an adjacent community. Even if the new population is of a different species, it can approximately fill the niche vacated by the extinct population and keep the food web intact.
Paragraph 1: Plant communities assemble themselves flexibly, and their particular structure depends on the specific history of the area. Ecologists use the term "succession" to refer to the changes that happen in plant communities and ecosystems over time. The first community in a succession is called a pioneer community, while the long-lived community at the end of succession is called a climax community. Pioneer and successional plant communities are said to change over periods from 1 to 500 years. These changes-in plant numbers and the mix of species-are cumulative. Climax communities themselves change but over periods of time greater than about 500 years.
托福TPO3閱讀真題題目Part3
1. The word "particular" in the passage is closest in meaning to
○natural
○final
○specific
○complex
2. According to paragraph 1, which of the following is NOT true of climax communities?
○They occur at the end of a succession.
○They last longer than any other type of community.
○The numbers of plants in them and the mix of species do not change.
○They remain stable for at least 500 years at a time.
Paragraph 2: An ecologist who studies a pond today may well find it relatively unchanged in a year's time. Individual fish may be replaced, but the number of fish will tend to be the same from one year to the next. We can say that the properties of an ecosystem are more stable than the individual organisms that compose the ecosystem.
3. According to paragraph 2, which of the following principles of ecosystems can be learned by studying a pond?
○Ecosystem properties change more slowly than individuals in the system.
○The stability of an ecosystem tends to change as individuals are replaced.
○Individual organisms are stable from one year to the next.
○A change in the members of an organism does not affect an ecosystem's properties.
Paragraph 3: At one time, ecologists believed that species diversity made ecosystems stable. They believed that the greater the diversity the more stable the ecosystem. Support for this idea came from the observation that long-lasting climax communities usually have more complex food webs and more species diversity than pioneer communities. Ecologists concluded that the apparent stability of climax ecosystems depended on their complexity. To take an extreme example, farmlands dominated by a single crop are so unstable that one year of bad weather or the invasion of a single pest can destroy the entire crop. In contrast, a complex climax community, such as a temperate forest, will tolerate considerable damage from weather to pests.
4. According to paragraph 3, ecologists once believed that which of the following illustrated the most stable ecosystems?
○Pioneer communities
○Climax communities
○Single-crop farmlands
○Successional plant communities
Paragraph 4: The question of ecosystem stability is complicated, however. The first problem is that ecologists do not all agree what "stability" means. Stability can be defined as simply lack of change. In that case, the climax community would be considered the most stable, since, by definition, it changes the least over time. Alternatively, stability can be defined as the speed with which an ecosystem returns to a particular form following a major disturbance, such as a fire. This kind of stability is also called resilience. In that case, climax communities would be the most fragile and the least stable, since they can require hundreds of years to return to the climax state.
5. According to paragraph 4, why is the question of ecosystem stability complicated?
○The reasons for ecosystem change are not always clear.
○Ecologists often confuse the word "stability" with the word "resilience."
○The exact meaning of the word "stability" is debated by ecologists.
○There are many different answers to ecological questions.
6. According to paragraph 4, which of the following is true of climax communities?○They are more resilient than pioneer communities.
○They can be considered both the most and the least stable communities.
○They are stable because they recover quickly after major disturbances.
○They are the most resilient communities because they change the least over time.
Paragraph 5: Even the kind of stability defined as simple lack of change is not always associated with maximum diversity. At least in temperate zones, maximum diversity is often found in mid-successional stages, not in the climax community. once a redwood forest matures, for example, the kinds of species and the number of individuals growing on the forest floor are reduced. In general, diversity, by itself, does not ensure stability. Mathematical models of ecosystems likewise suggest that diversity does not guarantee ecosystem stability-just the opposite, in fact. A more complicated system is, in general, more likely than a simple system to break down. A fifteen-speed racing bicycle is more likely to break down than a child's tricycle.
7. Which of the following can be inferred from paragraph 5 about redwood forests?
○They become less stable as they mature.
○They support many species when they reach climax.
○They are found in temperate zones.
○They have reduced diversity during mid-successional stages.
8. The word "guarantee" in the passage is closest in meaning to
○increase
○ensure
○favor
○complicate
9. In paragraph 5, why does the author provide the information that "A fifteen-speed racing bicycle is more likely to break down than a child's tricycle"?
○To illustrate a general principle about the stability of systems by using an everyday example
○To demonstrate that an understanding of stability in ecosystems can be applied to help understand stability in other situations
○To make a comparison that supports the claim that, in general, stability increases with diversity
○To provide an example that contradicts mathematical models of ecosystems
Paragraph 6: Ecologists are especially interested to know what factors contribute to the resilience of communities because climax communities all over the world are being severely damaged or destroyed by human activities. The destruction caused by the volcanic explosion of Mount St. Helens, in the northwestern United States, for example, pales in comparison to the destruction caused by humans. We need to know what aspects of a community are most important to the community's resistance to destruction, as well as its recovery.
10. The word "pales" in the passage is closest in meaning to
○increases proportionally
○differs
○loses significance
○is common
Paragraph 7: Many ecologists now think that the relative long-term stability of climax communities comes not from diversity but from the "patchiness" of the environment, an environment that varies from place to place supports more kinds of organisms than an environment that is uniform. A local population that goes extinct is quickly replaced by immigrants from an adjacentcommunity. Even if the new population is of a different species, it can approximately fill the niche vacated by the extinct population and keep the food web intact.
11.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incurred choices change the meaning in important ways or leave out essential information.
○Ecologists now think that the stability of an environment is a result of diversity rather than patchiness.
○Patchy environments that vary from place to place do not often have high species diversity.
○Uniform environments cannot be climax communities because they do not support as many types of organisms as patchy environments.
○A patchy environment is thought to increase stability because it is able to support a wide variety of organisms.
12.The word "adjacent" in the passage is closest in meaning to
○foreign
○stable
○fluid
○neighboring
Paragraph 6: █Ecologists are especially interested to know what factors contribute to the resilience of communities because climax communities all over the world are being severely damaged or destroyed by human activities. █The destruction caused by the volcanic explosion of Mount St. Helens, in the northwestern United States, for example, pales in comparison to the destruction caused by humans. █We need to know what aspects of a community are most important to the community's resistance to destruction, as well as its recovery. █
13.Look at the four squares [█] that indicate where the following sentence could be added to the passage.
In fact, damage to the environment by humans is often much more severe than damage by natural events and processes.
Where would the sentence best fit? Click on a square to add the sentence to the passage.
14.Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some sentences do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points.
The process of succession and the stability of a climax community can change over time.
●
●
●
Answer choices
○The changes that occur in an ecosystem from the pioneer to the climax community can be seen in one human generation.
○A high degree of species diversity does not always result in a stable ecosystem.
○The level of resilience in a plant community contributes to its long-term stability.
○Ecologists agree that climax communities are the most stable types of ecosystems.
○Disagreements over the meaning of the term "stability" make it difficult to identify the most stable ecosystems.
○The resilience of climax communities makes them resistant to destruction caused by humans
托福TPO3閱讀真題答案Part3
參考答案：
1. ○3
2. ○3
3. ○1
4. ○2
5. ○3
6. ○2
7. ○3
8. ○2
9. ○1
10. ○3
11. ○4
12. ○4
13. ○2
14. A high degree of species diversity
The level of resilience in
Disagreements over the
托福TPO3閱讀翻譯Part3
參考翻譯：生態(tài)系統(tǒng)的長(zhǎng)期穩(wěn)定
植物群體可以自由地聚集，它們特殊的結(jié)構(gòu)取決于聚集區(qū)域的具體歷史。生態(tài)學(xué)家使用"演替"來(lái)詮釋植物群落和生態(tài)系統(tǒng)隨著時(shí)間推移所發(fā)生的變化。演替中的第一個(gè)群落被稱作先鋒群落，而處于演替最后那個(gè)長(zhǎng)期生存的群落被稱為頂極群落。先鋒群落和緊接著的植物群落的變化周期是從1到500年不等，植物數(shù)量和混合種類數(shù)量的變化是慢慢積累的。頂極群落本身也改變，但其變化周期超過(guò)500年。
現(xiàn)代一個(gè)研究池塘的生態(tài)學(xué)會(huì)發(fā)現(xiàn)池塘在一年當(dāng)中相對(duì)而言是不變的。個(gè)別魚類可能被替換，但年復(fù)一年魚的總數(shù)都趨于一致。也就是說(shuō)，一個(gè)生態(tài)系統(tǒng)自身的屬性要比由單一生物體組成的生態(tài)系統(tǒng)更穩(wěn)定。
生態(tài)學(xué)家們一度認(rèn)為物種的多樣性使生態(tài)系統(tǒng)穩(wěn)定，生態(tài)系統(tǒng)物種越多樣則生態(tài)系統(tǒng)越穩(wěn)定。通過(guò)觀察得出的結(jié)論支持了這個(gè)觀點(diǎn)，長(zhǎng)期持久的頂極群落通常要比先鋒群落具備更為復(fù)雜的食物網(wǎng)和更多的物種。生態(tài)學(xué)家家們得出的結(jié)論是：頂點(diǎn)生態(tài)系統(tǒng)的穩(wěn)定性明顯取決于他們的復(fù)雜化程度。舉個(gè)極端的例子，在單一作物的農(nóng)田中，一年的惡劣天氣或單一害蟲的入侵就可以摧毀所有作物。與此相反，在一個(gè)復(fù)雜的頂極群落里，如溫帶森林，他們便可以抵御來(lái)自氣候和害蟲的干擾和入侵。
不管怎樣，生態(tài)系統(tǒng)穩(wěn)定性的問(wèn)題非常復(fù)雜。首先，不是所有的生態(tài)學(xué)家都贊同"穩(wěn)定"的含義。穩(wěn)定性可以簡(jiǎn)單地定義為缺乏變化。如果是這樣的話，頂極群落將被視為最穩(wěn)定的，因?yàn)楦鶕?jù)定義，他們隨著時(shí)間推移而變化得最少。另外，穩(wěn)定性也可以界定為生態(tài)系統(tǒng)在經(jīng)歷了嚴(yán)重破壞之后回復(fù)原貌的速度，比如火災(zāi)。這種穩(wěn)定性也被稱作彈性。在這種情況下，頂極群落將是最脆弱和最不穩(wěn)定的，因?yàn)樗麄兛赡苄枰獢?shù)百年時(shí)間才能恢復(fù)到頂點(diǎn)狀態(tài)。
即使是這種被定義為簡(jiǎn)單地缺乏變化的穩(wěn)定性并非總是與最多樣的物種聯(lián)系起來(lái)。至少在溫帶地區(qū)，會(huì)經(jīng)常在演替過(guò)程中發(fā)現(xiàn)最多物種，而不是在頂極群落中。例如，紅杉樹林一旦成熟，其中的物種數(shù)量以及單個(gè)物種的數(shù)量都會(huì)減少。一般來(lái)說(shuō)，多樣性本身并不能保證穩(wěn)定性(事實(shí)上正相反)，生態(tài)系統(tǒng)的數(shù)學(xué)模型也可以得出同樣的結(jié)論。一個(gè)更復(fù)雜的系統(tǒng)可能比一個(gè)簡(jiǎn)單的系統(tǒng)更容易被破壞(一個(gè)十五速的 賽車 比一個(gè)孩子的三輪車更容易損壞)。
生態(tài)學(xué)家們更想弄清楚到底哪些因素有助于促成群落的恢復(fù)，因?yàn)槭澜绺鞯氐捻敇O群落都因?yàn)槿祟惢顒?dòng)而遭受到嚴(yán)重的損壞或毀壞。就像美國(guó)西北部圣海倫火山的猛烈噴發(fā)所造成的破壞，在人類活動(dòng)對(duì)環(huán)境造成的破壞面前也相形見(jiàn)絀。我們必須了解對(duì)群落抵抗、破壞和恢復(fù)來(lái)說(shuō)哪些是最重要的。
現(xiàn)在的很多生態(tài)學(xué)家們認(rèn)為，頂極群落相對(duì)長(zhǎng)期的穩(wěn)定性并非來(lái)自于多樣性，而是來(lái)自環(huán)境的"補(bǔ)綴"，隨處變化的環(huán)境比始終如一的環(huán)境更有利于多種有機(jī)體的生存。當(dāng)?shù)匚锓N滅亡后，馬上就會(huì)被相鄰群落的移民取代。即便是另一種不同的物種，他們也可以填補(bǔ)那些已滅絕生物的空缺，并保持食物網(wǎng)的完整。
托福TPO3閱讀真題原文及答案翻譯Part3相關(guān) 文章 ：
1. 新托福閱讀考試需要多長(zhǎng)時(shí)間
錯(cuò)15個(gè)得16分。
托福?？糡PO2閱讀部分整體42道題，對(duì)應(yīng)原始分?jǐn)?shù)滿分45分，轉(zhuǎn)換為標(biāo)準(zhǔn)分后滿分為30分，通過(guò)查表將會(huì)給出原始分?jǐn)?shù)與最終分?jǐn)?shù)的對(duì)應(yīng)。
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