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托福阅读TPO16(试题+答案+译文)第2篇

TPO是我们常用的托福模考工具,对我们的备考很有价值,下面我给大家带来托福阅读TPO16(试题+答案+译文)第2篇:Development of the Periodic Table。

托福阅读原文

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.

托福阅读试题

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 阅读答案

1.interplay相互作用,所以D的interaction正确。从单词本身看,inter表示在……之间,play是起到什么什么作用,所以interplay是相互作用。原句说观察、预测与实验相互作用,所以答案是interaction,A顺序B解释C要求都错。

2.以increasing atomic mass做关键词定位至倒数第三句,说把元素按照原子量增加的顺序排布,发现相邻元素属于不同的族,族的顺序是固定的,每隔固定数量的元素会重现。所以正确答案是C。A的alkali metals,B的same atomic mass原文都没说;D说相邻元素性质相近与原文相反。

3.修辞目的题,先找到两个人名,说两个人都非常有远见,在周期表中给没发现的元素留了空隙,也就是A说的他们足够自信认为元素周期律适用于所有元素;B的wrong和C的unwilling都跟原文说反;D的disagreement原文没说。

4.修辞目的题,先找到两个人名,说门捷列夫比梅伊尔更胆儿大,他推测如果用来在周期表中排序的原子量与元素周期律互相冲突的时候,就说明原子量错了,也就是选项B说的门捷列夫认为以前被大家所认识到的一些东西是错的。两个人的意见是一样的,只是门捷列夫更进一步,所以A和C说两者的意见有差异不对;D说不是按原子量排序的错。

5.以changing the atomic mass of indium做关键词定位至第六句,说由于元素周期表中砷和硒之间没有空位,所以铟的原子量是错的。因为前面说如果原子量把元素放错了位置,就说明原子量是错的,后一句是为了证明这个观点的,所以答案是A。B的experimental evidence和D的化学性质相似原文都没说;C有space与原文相反。

6.以tellerium coms before iodine做关键词定位至倒数第五句for example处,但这句话只是一个例子,所以往前看,说元素不应该严格按照原子量排列,而且最后一句又说决定元素化学性质的是原子序数,不是原子量,也就是应该按照原序数量排列,所以答案D正确。A谁common谁不common,B有没有同位素还有C的化学性质多变没有信息能推出。

7.abundance丰度,答案是plenty。原句说这种异常,也就是尽管原子量大却排在前面这种异常是由于同位素的什么,然后后面就解释每种同位素的原子序数相同,但中子数不同,导致原子量不同,猜到每种同位素的多少不同,所以答案plenty,B要求D顺序明显不对;A重量不同原文已经直接说了不用再说一遍。

8.analogous to可类比的,相似的,所以答案similar to正确。原句说铝元素之下的空格表明一个性质与铝怎么样的元素的存在,前文都说了相邻的元素属于不同的族,而且族会相隔固定数目的元素出现,而且根据常识也知道元素周期表中上下两元素性质相似,所以答案是similar。A实现预测的是人,不是铝元素的性质;B期待不靠谱;D谁比谁好原文没说。

9.以eka-aluminum做关键词定位至第三句,但这句话只说了预测了eka的性质,没说根据什么预测的,看上一句,说eka是铝之下的那个空格里的元素,而且跟铝性质相似,所以答案是B,eka要填的那个空格。A铝的原子量C另外五个没发现的元素D的gallium原文都没说。

10.gallium做关键词定位至倒数第三句,但这句话只是说命名为GA,没说支持什么,往下看说GA的发现支持了元素周期律,而问题刚好是问GA的发现支持了什么,所以答案是C,元素周期表的组成规律,也就是元素周期律。

11.原文的结构是R研究了一种气体,并且发现这种气体是氦,所以答案是D。A完全搞乱了原文的结构,氦在太阳光谱中不是R发现的;B的转折关系错;C和A的错误相似,氦在太阳光谱中不是R发现的。

12.postulate推断,推测,所以hypothesize正确。原句说这两个人怎么样一个新的元素族的存在,接着后面的人分离出了这些元素,既然是后面的人分离的,discover和report就不对,因为这两个词有他们两个发现的意思;generate完全不对,这两个人不能产生元素。

13.三个过渡点,分别是名词chemical groups,名词sequence和动词词组repeat itself,这几个点都可以确定B或者C是答案,但B前后的atomic mass说明两句话的过渡是非常紧密的,所以B被排除,答案是C。

14.Lord选项错,原文没说他的研究提供了元素周期表限制元素数量的证据,不选。Ramsay and Lord选项错,原文没说他们俩挑战了卡文迪许,不选。Isotopes选项是原文第二段中的一个细节,不选。Mendeleyev and Meyer选项对应原文第一段后半部分,正确。Mendeleyev’s选项对应原文第三段最后两句,正确。In the 1890’s选项对应全文最后一句话,正确。

托福阅读译文

元素周期表是按原子序数(元素原子核中质子的数量)由小到大依次排列,反映化学周期性和元素的物理特征的图表。这一科学发现具有里程碑的意义,它进一步证明了科学探索过程中观察、预测和实证之间的根本联系。19世纪一开始,科学家们不断探索新的元素。到19世纪60年代后期,已经发现了60种以上的化学元素,而许多描述性化学被认知。人们提出各种建议,认为该基于化学和物理特征的相似性将化学元素排列成组。他们接下来又证实了元素的族群特性(物理或是化学相似性)和原子质量(一种元素的单个原子的测量质量)之间存在联系。当时元素还是按照原子质量从小到大排列,人们发现,一些具备连续性的元素却分属不同的化学组,并且发现在这种排列方式下,元素群组的顺序是固定的且定期重复。因此,当每一新行都以碱性金属元素开始并逐步将这一系列的元素排列出来时,元素周期表中同一组中的元素就会自动归入一个垂直纵列中。这个表格就是现代元素周期表的雏形。

当德国化学家迈耶(Lother Meyer)和(彼此独立的)俄国化学家门捷列夫在1869年到1870年间首次发布元素周期表时,有三分之一的天然化学元素还没被发现。然而这两位化学家都极富远见,他们在周期表上留白,对元素物理性和化学性的分析空白处还有新的元素有待发现。门捷列夫比迈耶更为大胆,他甚至做出假设,如果周期表按原子质量排列,但元素位置不对的话,那么原子质量也是错的。在某些情况下,这个设想是正确的。以铟为例,先前测量出铟的原子质量在砷和硒之间。但是因为在周期表中这两个元素之间没有缝隙,由此门捷列夫提出铟的原子质量变为截然不同的一个值,这样就可以将其置于镉和锡之间的空位。事实上,接下来的研究表明,元素周期表中元素不能严格按照原子质量排列。例如,尽管碲的原子质量比碘略大,但在元素周期表中,它却排在碘前面。出现这种反常现象,主要是因为相对丰富的“同位素 ”或者各种元素的多样性。同一元素的所有同位素具有相同的质子数,但中子数不同,因此它们的原子质量也不一样。一个特定元素的同位素具有相同的化学特征,但在物理性质上有一些细微差异。现在我们知道,是原子数目(原子核中质子的数量)而非原子质量(质子和中子的数量)决定着元素的化学性质。

门捷列夫在另一个研究上也比迈耶更为深入:他预测还有六种元素的性质待被发现。例如,就在铝下面有一个空位,这表明还有一个性质和铝类似的新元素存在。门捷列夫将该元素定义为“铝下元素 ”(eka是梵语词,意思是 “下一个”)并且还预测了其性质。仅仅5年之后,原子质量相吻合的元素就被分离出来,发现者将其命名为“镓”。镓所表现出的特性和门捷列夫对“铝下元素”的预测一一对应,这为元素法则提供了一个强有力的依据。还有一个例证,1885年发现“硅下元素”,同样为门捷列夫所预测,后来命名为锗。

元素周期表的框架似乎限制了可能存在的元素数量。因此,当约翰?威廉姆?斯特拉特(瑞利男爵),在1894年发现一种气态元素不能适应之前的元素表时会非常惊讶。一个世纪以前,亨利?卡文迪许就注意到,当氧气和氮气从空气中被移除后仍然有残余气体存在,但当时没人意识到其中的重要性。瑞利和威廉?拉姆齐一道,共同分离出一种气体(将之与其他物质隔离并存于一个真空环境)并将其命名为氩。拉姆齐经过研究又发现了另一种存在于自然界中的气体元素——氦,该元素在太阳中存在,并且很早就被发现存在于太阳光谱中,但是之前并没有在地球上找到过。瑞利和拉姆齐做出假设,认为存在一组新元素, 1898年,这一系列元素中的其他元素(氖,氪,氙)也被成功分离出来。

具有相同质子数,不同中子数(或不同质量数)同一元素的不同核素互为同位素(Isotopes)。

Eka是一个用来为在元素周期表中位于某个元素下面的位置的化学元素命名的前缀。前缀eka-尤其用于命名尚未发现的元素。例如,在发现锗以前它被称为硅下元素(eka-硅,ekasilicon)。

托福阅读TPO16(试题+答案+译文)第2篇相关 文章 :

托福TPO7阅读原文及参考答案Part1

托福TPO是托福阅读答案我们托福阅读托福阅读答案的重要参考资料,为了方便大家备考,下面我给大家整理了托福TPO1阅读文本及题目答案Part2,希望大家喜欢。

        托福TPO7阅读原文Part1

The Geologic History of the Mediterranean

In 1970 geologists Kenneth J. Hsu and William B.F. Ryan were collecting research data while aboard the oceanographic research vessel Glomar Challenger. An objective of this particular cruise was to investigate the floor of the Mediterranean and to resolve questions about its geologic history. One question was related to evidence that the invertebrate fauna (animals without spines) of the Mediterranean had changed abruptly about 6 million years ago. Most of the older organisms were nearly wiped out, although a few hardy species survived. A few managed to migrate into the Atlantic. Somewhat later, the migrants returned, bringing new species with them. Why did the near extinction and migrations occur?

Another task for the Glomar Challenger's scientists was to try to determine the origin of the domelike masses buried deep beneath the Mediterranean seafloor. These structures had been detected years earlier by echo-sounding instruments, but they had never been penetrated in the course of drilling. Were they salt domes such as are common along the United States Gulf Coast, and if so, why should there have been so much solid crystalline salt beneath the floor of the Mediterranean?

With question such as these clearly before them, the scientists aboard the Glomar Challenger processed to the Mediterranean to search for the answers. On August 23, 1970, they recovered a sample. The sample consisted of pebbles of hardened sediment that had once been soft, deep-sea mud, as well as granules of gypsum and fragments of volcanic rock. Not a single pebble was found that might have indicated that the pebbles came from the nearby continent. In the days following, samples of solid gypsum were repeatedly brought on deck as drilling operations penetrated the seafloor. Furthermore, the gypsum was found to possess peculiarities of composition and structure that suggested it had formed on desert flats. Sediment above and below the gypsum layer contained tiny marine fossils, indicating open-ocean conditions. As they drilled into the central and deepest part of the Mediterranean basin, the scientists took solid, shiny, crystalline salt from the core barrel. Interbedded with the salt were thin layers of what appeared to be windblown silt.

The time had come to formulate a hypothesis. The investigators theorized that about 20 million years ago, the Mediterranean was a broad seaway linked to the Atlantic by two narrow straits. Crustal movements closed the straits, and the landlocked Mediterranean began to evaporate. Increasing salinity caused by the evaporation resulted in the extermination of scores of invertebrate species. Only a few organisms especially tolerant of very salty conditions remained. As evaporation continued, the remaining brine (salt water) became so dense that the calcium sulfate of the hard layer was precipitated. In the central deeper part of the basin, the last of the brine evaporated to precipitate more soluble sodium chloride (salt). Later, under the weight of overlying sediments, this salt flowed plastically upward to form salt domes. Before this happened, however, the Mediterranean was a vast desert 3,000 meters deep. Then, about 5.5 million years ago came the deluge. As a result of crustal adjustments and faulting, the Strait of Gibraltar, where the Mediterranean now connects to the Atlantic, opened, and water cascaded spectacularly back into the Mediterranean. Turbulent waters tore into the hardened salt flats, broke them up, and ground them into the pebbles observed in the first sample taken by the Challenger. As the basin was refilled, normal marine organisms returned. Soon layer of oceanic ooze began to accumulate above the old hard layer.

The salt and gypsum, the faunal changes, and the unusual gravel provided abundant evidence that the Mediterranean was once a desert.

gypsum: a mineral made of calcium sulfate and water

Paragraph 1: In 1970 geologists Kenneth J. Hsu and William B.F. Ryan were collecting research data while aboard the oceanographic research vessel Glomar Challenger. An objective of this particular cruise was to investigate the floor of the Mediterranean and to resolve questions about its geologic history. One question was related to evidence that the invertebrate fauna (animals without spines) of the Mediterranean had changed abruptly about 6 million years ago. Most of the older organisms were nearly wiped out, although a few hardy species survived. A few managed to migrate into the Atlantic. Somewhat later, the migrants returned, bringing new species with them. Why did the near extinction and migrations occur?

   托福TPO7阅读题目Part1

1. The word "objective" in the passage is closest in meaning to

○achievement

○requirement

○purpose

○feature

2. Which of the following is NOT mentioned in paragraph 1 as a change that occurred in the fauna of the Mediterranean?

○Most invertebrate species disappeared during a wave of extinctions.

○A few hardy species wiped out many of the Mediterranean's invertebrates.

○Some invertebrates migrated to Atlantic Ocean.

○New species of fauna populated the Mediterranean when the old migrants returned.

Paragraph 3: With question such as these clearly before them, the scientists aboard the Glomar Challenger processed to the Mediterranean to search for the answers. On August 23, 1970, they recovered a sample. The sample consisted of pebbles of hardened sediment that had once been soft, deep-sea mud, as well as granules of gypsum and fragments of volcanic rock. Not a single pebble was found that might have indicated that the pebbles came from the nearby continent. In the days following, samples of solid gypsum were repeatedly brought on deck as drilling operations penetrated the seafloor. Furthermore, the gypsum was found to possess peculiarities of composition and structure that suggested it had formed on desert flats. Sediment above and below the gypsum layer contained tiny marine fossils, indicating open-ocean conditions. As they drilled into the central and deepest part of the Mediterranean basin, the scientists took solid, shiny, crystalline salt from the core barrel. Interbedded with the salt were thin layers of what appeared to be windblown silt.

3. What does the author imply by saying "Not a single pebble was found that might have indicated that the

pebbles came from the nearby continent"?

○The most obvious explanation for the origin of the pebbles was not supported by the evidence.

○The geologists did not find as many pebbles as they expected.

○The geologists were looking for a particular kind of pebble.

○The different pebbles could not have come from only one source.

4.Which of the following can be inferred from paragraph 3 about the solid gypsum layer?

○It did not contain any marine fossil.

○It had formed in open-ocean conditions.

○It had once been soft, deep-sea mud.

○It contained sediment from nearby deserts.

5. Select the TWO answer choice from paragraph 3 that identify materials discovered in the deepest part of the Mediterranean basin. To receive credit you must select TWO answers.

○Volcanic rock fragments.

○Thin silt layers

○Soft, deep-sea mud

○Crystalline salt

6. What is the main purpose of paragraph 3?

○To describe the physical evidence collected by Hsu and Ryan

○To explain why some of the questions posed earlier in the passage could not be answered by the findings of the Glomar Challenger

○To evaluate techniques used by Hsu and Ryan to explore the sea floor

○To describe the most difficult problems faced by the Glomar Challenger expedition

Paragraph 4: The time had come to formulate a hypothesis. The investigators theorized that about 20 million years ago, the Mediterranean was a broad seaway linked to the Atlantic by two narrow straits. Crustal movements closed the straits, and the landlocked Mediterranean began to evaporate. Increasing salinity caused by the evaporation resulted in the extermination of scoresof invertebrate species. Only a few organisms especially tolerant of very salty conditions remained. As evaporation continued, the remaining brine (salt water) became so dense that the calcium sulfate of the hard layer was precipitated. In the central deeper part of the basin, the last of the brine evaporated to precipitate more soluble sodium chloride (salt). Later, under the weight of overlying sediments, this salt flowed plastically upward to form salt domes. Before this happened, however, the Mediterranean was a vast desert 3,000 meters deep. Then, about 5.5 million years ago came the deluge. As a result of crustal adjustments and faulting, the Strait of Gibraltar, where the Mediterranean now connects to the Atlantic, opened, and water cascaded spectacularly back into the Mediterranean. Turbulent waters tore into the hardened salt flats, broke them up, and ground them into the pebbles observed in the first sample taken by the Challenger. As the basin was refilled, normal marine organisms returned. Soon layer of oceanic ooze began to accumulate above the old hard layer.

7. According to paragraph 4, which of the following was responsible for the evaporation of the Mediterranean's waters?

○The movements of Earth's crust

○The accumulation of sediment layers

○Changes in the water level of the Atlantic Ocean

○Changes in Earth's temperature

8. The word "scores" in the passage is closest in meaning to

○members

○large numbers

○populations

○different types

9. According to paragraph 4, what caused most invertebrate species in the Mediterranean to become extinct?

○The evaporation of chemicals necessary for their survival

○Crustal movements that connected the Mediterranean to the saltier Atlantic

○The migration of new species through the narrow straits

○Their inability to tolerate the increasing salt content of the Mediterranean

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.

○The strait of Gibraltar reopened when the Mediterranean and the Atlantic became connected and the cascades of water from one sea to the other caused crustal adjustments and faulting.

○The Mediterranean was dramatically refilled by water from the Atlantic when crustal adjustments and faulting opened the Strait of Gibraltar, the place where the two seas are joined.

○The cascades of water from the Atlantic to the Mediterranean were not as spectacular as the crustal adjustments and faulting that occurred when the Strait of Gibraltar was connected to those seas.

○As a result of crustal adjustments and faulting and the creation of the Strait of Gibraltar, the Atlantic and Mediterranean were connected and became a single sea with spectacular cascades of water between them.

11. The word "Turbulent" in the passage is closest in meaning to

○Fresh

○Deep

○Violent

○Temperate

Paragraph 2 ■Another task for the Glomar Challenger's scientists was to try to determine the origin of the domelike masses buried deep beneath the Mediterranean seafloor. ■These structures had been detected years earlier by echo-sounding instruments, but they had never been penetrated in the course of drilling. ■Were they salt domes such as are common along the United States Gulf Coast, and if so, why should there have been so much solid crystalline salt beneath the floor of the Mediterranean? ■

12. Look at the four squares [■] that indicate where the following sentence could be added to the passage.

Thus, scientists had information about the shape of the domes but not about their chemical composition and origin.

Where would the sentence best fit?

13.Direction: 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.

An expedition to the Mediterranean answered some long-standing questions about the ocean's history.

Answer choices

○The Glomar Challenger expedition investigated changes in invertebrate fauna and some unusual geologic features.

○Researchers collected fossils to determine which new species migrated from the Atlantic with older species.

○Scientists aboard the Glomar Challenger were the first to discover the existence of domelike masses underneath the seafloor.

○Samples recovered from the expedition revealed important differences in chemical composition and fossil distribution among the sediment layers.

○Evidence collected by the Glomar Challenger supports geologists' beliefs that the Mediterranean had evaporated and become a desert, before it refilled with water.

○Mediterranean salt domes formed after crustal movements opened the straits between the Mediterranean and the Atlantic, and the Mediterranean refilled with water.

托福TPO7 阅读答案 Part1

参考答案托福阅读答案

1.○ 3

2.○ 2

3.○ 1

4.○ 1

5.○ 2, 4

6.○ 1

7.○ 1

8○ 2

9.○ 4

10.○ 2

11.○ 3

12.○ 3

13. The Glomar Challenger

Samples recovered from

Evidence collected by

托福TPO7阅读原文翻译Part1

参考翻译:地中海的地质历史

1970年,地理学家Kenneth J. Hsu 和 William B.F. Ryan在海洋调查船Glomar Challenger号上收集调研资料。这次特别巡航的一个目的是调查地中海的地层以及解决关于其地质历史的问题。其中一个问题是有关地中海地区无脊椎动物(没有脊椎的动物)于600万年前发生剧变的证据。大部分更加古老的生物都几乎灭绝了,尽管一些顽强的种类得以生存。很少的一些动物成功地迁移到了大西洋。不久后,这些动物又回来了,并带回来新的物种。为什么这次较近的动物灭绝和迁移会发生呢?

Glomar Challenger号上科学家们的另一个任务是尝试去确定深埋在地中海海底穹顶状巨块的起源。这些结构在早些年被回声探测器探测过,但是它们从未被钻探过。它们是像美国墨西哥海湾海岸一带的含盐穹顶状巨块吗?如果是的话,为什么在地中海海底之下会有这么多固体的结晶盐呢?

带着这些清楚摆在他们面前的问题,科学家们登上Glomar Challenger号前往地中海寻找答案。1970年8月23日,他们找到了一个样本。这个样本由石膏块和火山岩碎块组成。周围没有发现一块能说明这些小石头来自附近的大陆。接下来的日子里,随着海底岩层钻探实验的进行,固体石膏样本被不断地放在甲板上。而且,这些膏状物的组成和结构特性表明它们形成于沙漠。在石膏层上下的沉积物中包含了微小的海洋生物化石,说明了这是开放性的海洋环境。当钻到地中海盆地中心的最深处时,科学家们从钻管中获得了坚实的、光亮的结晶盐。跟结晶盐嵌在一起的薄层像是被风吹起的泥沙层。

时间阐明了一个假设。调查者们构思了这样的理论:大约2 000万年前,地中海是一条宽阔的航道,它通过两条狭窄的海峡与大西洋连接。地壳运动封闭了海峡,被陆地包围的地中海也开始蒸发。由蒸发引起的越来越高的盐度造成无脊椎动物种类的灭绝。只有一些能抵抗高盐度条件的物种保留下来。随着蒸发的继续进行,盐水浓度太高以致硬地层的硫酸钙发生沉淀。在盆地的中间深处,剩余盐水的持续蒸发形成更多的可溶的氯化钠(盐)。后来,在上层沉淀物的重压下,盐向上形成了含盐的圆顶。然而在这之前,地中海是一个3 000米深的大沙漠。然后,550万年前发生了洪水。作为地壳调整和断层作用的结果,现在连接地中海和大西洋的直布罗陀海峡打开了,水流像瀑布一样壮观地涌回地中海。湍急的水流冲击并摧毁了坚硬的含盐层,把它们磨成了Challenger号获得的第一份样本中人们所观察到的鹅卵石。随着盆地的填充,普通的海洋生物又回来了。不久后海洋软泥层开始在原先的硬地层上堆积。

盐、石膏、动物区系的变更,还有不寻常的沙砾层都为地中海曾经是片沙漠的理论提供了充分的证据。

托福TPO7阅读原文及参考答案Part1相关 文章 :

托福TPO1阅读真题原文及答案翻译part3

相信备考托福的同学都知道托福TPO的重要性,为了方便大家备考,下面我给大家整理出托福TPO1阅读真题原文及答案翻译,希望大家喜欢。

       托福TPO1阅读真题原文Part3

Timberline Vegetation on Mountains

The transition from forest to treeless tundra on a mountain slope is often a dramatic one. Within a vertical distance of just a few tens of meters, trees disappear as a life-form and are replaced by low shrubs, herbs, and grasses. This rapid zone of transition is called the upper timberline or tree line. In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.

The upper timberline, like the snow line, is highest in the tropics and lowest in the Polar Regions. It ranges from sea level in the Polar Regions to 4,500 meters in the dry subtropics and 3,500-4,500 meters in the moist tropics. Timberline trees are normally evergreens, suggesting that these have some advantage over deciduous trees (those that lose their leaves) in the extreme environments of the upper timberline. There are some areas, however, where broadleaf deciduous trees form the timberline. Species of birch, for example, may occur at the timberline in parts of the Himalayas.

At the upper timberline the trees begin to become twisted and deformed. This is particularly true for trees in the middle and upper latitudes, which tend to attain greater heights on ridges, whereas in the tropics the trees reach their greater heights in the valleys. This is because middle- and upper- latitude timberlines are strongly influenced by the duration and depth of the snow cover. As the snow is deeper and lasts longer in the valleys, trees tend to attain greater heights on the ridges, even though they are more exposed to high-velocity winds and poor, thin soils there. In the tropics, the valleys appear to be more favorable because they are less prone to dry out, they have less frost, and they have deeper soils.

There is still no universally agreed-on explanation for why there should be such a dramatic cessation of tree growth at the upper timberline. Various environmental factors may play a role. Too much snow, for example, can smother trees, and avalanches and snow creep can damage or destroy them. Late-lying snow reduces the effective growing season to the point where seedlings cannot establish themselves. Wind velocity also increases with altitude and may cause serious stress for trees, as is made evident by the deformed shapes at high altitudes. Some scientists have proposed that the presence of increasing levels of ultraviolet light with elevation may play a role, while browsing and grazing animals like the ibex may be another contributing factor. Probably the most important environmental factor is temperature, for if the growing season is too short and temperatures are too low, tree shoots and buds cannot mature sufficiently to survive the winter months.

Above the tree line there is a zone that is generally called alpine tundra. Immediately adjacent to the timberline, the tundra consists of a fairly complete cover of low-lying shrubs, herbs, and grasses, while higher up the number and diversity of species decrease until there is much bare ground with occasional mosses and lichens and some prostrate cushion plants. Some plants can even survive in favorable microhabitats above the snow line. The highest plants in the world occur at around 6,100 meters on Makalu in the Himalayas. At this great height, rocks, warmed by the sun, melt small snowdrifts.

The most striking characteristic of the plants of the alpine zone is their low growth form. This enables them to avoid the worst rigors of high winds and permits them to make use of the higher temperatures immediately adjacent to the ground surface. In an area where low temperatures are limiting to life, the importance of the additional heat near the surface is crucial. The low growth form can also permit the plants to take advantage of the insulation provided by a winter snow cover. In the equatorial mountains the low growth form is less prevalent.

Paragraph 1: The transition from forest to treeless tundra on a mountain slope is often adramatic one. Within a vertical distance of just a few tens of meters, trees disappear as a life-form and are replaced by low shrubs, herbs, and grasses. This rapid zone of transition is called the upper timberline or tree line. In many semiarid areas there is also a lower timberline where the forest passes into steppe or desert at its lower edge, usually because of a lack of moisture.

托福TPO1阅读真题题目Part3

1. The word "dramatic" in the passage is closest in meaning to

○gradual

○complex

○visible

○striking

2. Where is the lower timberline mentioned in paragraph 1 likely to be found?

○In an area that has little water

○In an area that has little sunlight

○Above a transition area

○On a mountain that has on upper timberline.

3. Which of the following can be inferred from paragraph 1 about both the upper and lower timberlines?

○Both are treeless zones.

○Both mark forest boundaries.

○Both are surrounded by desert areas.

○Both suffer from a lack of moisture.

Paragraph 2: The upper timberline, like the snow line, is highest in the tropics and lowest in the Polar Regions. It ranges from sea level in the Polar Regions to 4,500 meters in the dry subtropics and 3,500-4,500 meters in the moist tropics. Timberline trees are normally evergreens, suggesting that these have some advantage over deciduous trees (those that lose their leaves) in the extreme environments of the upper timberline. There are some areas, however, where broadleaf deciduous trees form the timberline. Species of birch, for example, may occur at the timberline in parts of the Himalayas.

4. Paragraph 2 supports which of the following statements about deciduous trees?

○They cannot grow in cold climates.

○They do not exist at the upper timberline.

○They are less likely than evergreens to survive at the upper timberline.

○They do not require as much moisture as evergreens do.

Paragraph 3: At the upper timberline the trees begin to become twisted and deformed. This is particularly true for trees in the middle and upper latitudes, which tend to attain greater heights on ridges, whereas in the tropics the trees reach their greater heights in the valleys. This is because middle- and upper- latitude timberlines are strongly influenced by the duration and depth of the snow cover. As the snow is deeper and lasts longer in the valleys, trees tend to attain greater heights on the ridges, even though they are more exposed to high-velocity winds and poor, thin soils there. In the tropics, the valleys appear to be more favorable because they are less prone to dry out, they have less frost, and they have deeper soils.

5. The word "attain" in the passage is closest in meaning to

○require

○resist

○achieve

○endure

6. The word "they" in the passage refers to

○valleys

○trees

○heights

○ridges

7. The word "prone" in the passage is closest in meaning to

○adapted

○likely

○difficult

○resistant

8. According to paragraph 3, which of the following is true of trees in the middle and upper latitudes?

○Tree growth is negatively affected by the snow cover in valleys

○Tree growth is greater in valleys than on ridges.

○Tree growth on ridges is not affected by high-velocity winds.

○Tree growth lasts longer in those latitudes than it does in the tropics.

Paragraph 4:There is still no universally agreed-on explanation for why there should be such a dramatic cessation of tree growth at the upper timberline. Various environmental factors may play a role. Too much snow, for example, can smother trees, and avalanches and snow creep can damage or destroy them. Late-lying snow reduces the effective growing season to the point where seedlings cannot establish themselves. Wind velocity also increases with altitude and may cause serious stress for trees, as is made evident by the deformed shapes at high altitudes. Some scientists have proposed that the presence of increasing levels of ultraviolet light with elevation may play a role, while browsing and grazing animals like the ibex may be another contributing factor. Probably the most important environmental factor is temperature, for if the growing season is too short and temperatures are too low, tree shoots and buds cannot mature sufficiently to survive the winter months.

9. Which of the sentences below best express the essential information in the highlighted sentence in the passage? In correct choices change the meaning in important ways or leave out essential information.

○Because of their deformed shapes at high altitudes, trees are not likely to be seriously harmed by the strong winds typical of those altitudes.

○As altitude increases, the velocity of winds increase, leading to a serious decrease in the number of trees found at high altitudes.

○The deformed shapes of trees at high altitudes show that wind velocity, which increase with altitude, can cause serious hardship for trees.

○Increased wind velocity at high altitudes deforms the shapes of trees, and this may cause serious stress for trees.

10. In paragraph 4, what is the author's main purpose in the discussion of the dramatic cessation of tree growth at the upper timberline?

○To argue that none of several environment factors that are believed to contribute to that phenomenon do in fact play a role in causing it.

○To argue in support of one particular explanation of that phenomenon against several competing explanations

○To explain why the primary environmental factor responsible for that phenomenon has not yet been identified

○To present several environmental factors that may contribute to a satisfactory explanation of that phenomenon

Paragraph 6: The most striking characteristic of the plants of the alpine zone is their low growth form. This enables them to avoid the worst rigors of high winds and permits them to make use of the higher temperatures immediately adjacent to the ground surface. In an area where low temperatures are limiting to life, the importance of the additional heat near the surface is crucial. The low growth form can also permit the plants to take advantage of the insulation provided by a winter snow cover. In the equatorial mountains the low growth form is lessprevalent.

11. The word "prevalent" in the passage is closest in meaning to

○predictable

○widespread

○successful

○developed

12. According to paragraph 6, all of the following statements are true of plants in the alpine zone EXCEPT:

○Because they are low, they are less exposed to strong winds.

○Because they are low, the winter snow cover gives them more protection from the extreme cold.

○In the equatorial mountains, they tend to be lower than in mountains elsewhere.

○Their low growth form keeps them closer to the ground, where there is more heat than further up.

Paragraph 5: Above the tree line there is a zone that is generally called alpine tundra. █Immediately adjacent to the timberline, the tundra consists of a fairly complete cover of low-lying shrubs, herbs, and grasses, while higher up the number and diversity of species decrease until there is much bare ground with occasional mosses and lichens and some prostrate cushion plants. █Some plants can even survive in favorable microhabitats above the snow line. The highest plants in the world occur at around 6,100 meters on Makalu in the Himalayas. █At this great height, rocks, warmed by the sun, melt small snowdrifts. █

13. Look at the four squares [█] that indicate where the following sentence could be added to the passage.

This explains how, for example, alpine cushion plants have been found growing at an altitude of 6,180 meters.

Where would the sentence best fit?

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.

At the timberline, whether upper or lower, there is a profound change in the growth of trees and other plants.

Answer choices

○Birch is one of the few species of tree that can survive in the extreme environments of the upper timberline.

○There is no agreement among scientists as to exactly why plant growth is sharply different above and below the upper timberline.

○The temperature at the upper timberline is probably more important in preventing tree growth than factors such as the amount of snowfall or the force of winds.

○The geographical location of an upper timberline has an impact on both the types of trees found there and their physical characteristics.

○High levels of ultraviolet light most likely play a greater role in determining tree growth at the upper timberline than do grazing animals such as the ibex.

○Despite being adjacent to the timberline, the alpine tundra is an area where certain kinds of low trees can endure high winds and very low temperatures

托福TPO1阅读真题答案Part3

答案:

1. ○4

2. ○1

3. ○2

4. ○3

5. ○3

6. ○2

7. ○2

8. ○1

9. ○3

10. ○4

11. ○2

12. ○3

13. ○4

14. There is no agreement among…

Despite being adjacent …

The geographical location of…

   托福TPO1阅读真题Part3原文翻译

山上树带界线的植被

通常从山坡上的森林到没有树的苔原是一种非常戏剧化的转变。在一个垂直距离只有几十米的地方,树木这种生命形式就消失了,取而代之的是低矮的灌木、草本植物和牧草。这种快速过渡的区域被称为上行树带界线或林木线。在许多干旱的地区存在着下行树带界线,在这里由于缺乏水分森林变成干草原,甚至在最下端会出现沙漠。

上行树带界线,和雪线一样,在热带最高,在极地最低。从极地地区的海平面到干燥的亚热带地区的海拔4 500米处以及潮湿的热带地区海拔3 500米至4 500米处都有上行树带界线。树带界线内通常是常绿树,它们和处于上行树带界线处极端恶劣环境中生长的落叶树木相比,具有一定的优势。然而,在部分地区也有由落叶阔叶林组成的树带界线。例如,在喜马拉雅的部分地区,桦树就在树带界线上。

上行树带界线的树木开始扭曲和变形,尤其在中高纬度地区的树木,这些地区的树木往往会在山脊上长得更高,而在热带地区的树木则在山谷里长得更高;因为中高纬度地区树带界线受积雪覆盖时间和深度的影响很大。由于山谷中积雪覆盖较厚且持续时间很长,树木即便是生长在大风和贫瘠的土地里,也往往会在山脊上长得更高。在热带地区山谷里更有利于生长,因为山谷不易干涸、很少结霜,并且有更深的土壤。

目前还没有一个普遍认同的解释来说明为什么会在树带界线上出现树木停止生长这种戏剧化的现象。多种环境因素都起到作用,例如,积雪过多会让树木透不过气,雪崩和雪移能摧毁树木;长时间积雪缩短了有效生长季节的时间,树苗无法生长;另外,风速会随着海拔的升高而增加,增加树木承受的压力,很明显,正是这种风速带来的压力导致树木在高纬度地区发生变形。一些科学家提出,随着海拔的上升而不断增强的紫外线、野生山羊等动物的放养,都是导致树带界线形成的因素。或许最重要的环境因素是温度,因为如果生长季节太短并且气温太低,树芽和树苗都无法充分地成长而存活过冬季。

在林木线之上有一个称为高山苔原的地带。由于紧挨着树带界线,苔原上都是矮灌木、草本植物和牧草。随着海拔的增加,物种的数量和多样性会逐渐减少,直到出现大量空地伴着零星的苔藓和地衣这样的伏地垫状植物。有些植物甚至可以在雪线以上有利的微环境中生存,世界上海拔最高的植物是出现在喜马拉雅山上6 100百米的马卡鲁峰。在这个高度上,被阳光温暖过的岩石可以将 小雪 堆融化。

高山植物最突出的特点是其低矮的生长形态。这种特点使他们能够避开大风最强势的势头,并且有助于他们利用紧邻地 面相 对较高的温度。在这样一个低温限制生命的地区,地表提供的额外温度是至关重要的。低矮的生长形态也可以帮助植物充分利用冬季积雪所提供的保温环境。在赤道区的山脉上低矮的生长形态并不常见。

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