『新东方在线托福阅读』为托福考生准备了ETS托福TPO/Official 43 Passage 2阅读练习：Look at the four squares  that indicate where the following sentence could be added to the passage. Because such muds are a major source of petroleum, scientists believe that petroleum originated as living organisms.  Where would the sentence best fit? Click on a square  to add the sentence to the passage.真题题目及答案解析，TPO/Official 43 Passage 2阅读原文范文音频翻译

托福TPO/Official 43 Passage 2阅读原文Look at the four squares  that indicate where the following sentence could be added to the passage. Because such muds are a major source of petroleum, scientists believe that petroleum originated as living organisms.  Where would the sentence best fit? Click on a square  to add the sentence to the passage.题目答案及解析-新东方托福官方网校手机版

石油被定义为一种气态，液态和半固态的天然存在的物质，主要由碳氢化合物（碳和氢的化学化合物）组成。

Petroleum is defined as a gaseous, liquid, and semisolid naturally occurring substance that consists chiefly of hydrocarbons (chemical compounds of carbon and hydrogen).

因此，石油是既包括油又包括天然气的术语。

Petroleum is therefore a term that includes both oil and natural gas.

石油几乎总是在海洋沉积岩中发现的。

Petroleum is nearly always found in marine sedimentary rocks.

在海洋中，微观浮游植物（微小的漂浮植物）和细菌（简单的单细胞生物）是被截留和埋藏在沉积物中有机物的主要来源。

In the ocean, microscopic phytoplankton (tiny floating plants) and bacteria (simple, single-celled organisms) are the principal sources of organic matter that is trapped and buried in sediment.

大多数有机物都埋在粘土中，然后慢慢转变成称为页岩的细颗粒沉积岩。

Most of the organic matter is buried in clay that is slowly converted to a fine-grained sedimentary rock known as shale.

在这种转化过程中，有机化合物转化为油和天然气。

During this conversion, organic compounds are transformed to oil and natural gas.

在大陆架和大陆斜坡底部采样表明，海底下的细泥含高达8％的有机物。

Sampling on the continental shelves and along the base of the continental slopes has shown that fine muds beneath the seafloor contain up to 8 percent organic matter.

石油是有机物分解的产物这一假说得到了另外两种证据的支持：石油具有只有从有机物中提取的碳氢化合物才具有的光学性质，石油含有氮和某些化合物，据说这些化合物只来源于生物物质。

Two additional kinds of evidence support the hypothesis that petroleum is a product of the decomposition of organic matter: oil possesses optical properties known only in hydrocarbons derived from organic matter, and oil contains nitrogen and certain compounds believed to originate only in living matter.

将原来的固体有机物转化为石油和天然气涉及到一系列复杂的化学反应，即使在石油和天然气形成之后，它们也可能发生额外的化学变化。

A complex sequence of chemical reactions is involved in converting the original solid organic matter to oil and gas, and additional chemical changes may occur in the oil and gas even after they have formed.

现在已经确定，石油会通过含水层迁移并可能被困在储层中。

It is now well established that petroleum migrates through aquifers and can become trapped in reservoirs.

Petroleum migration is analogous to groundwater migration.

当将石油和天然气从其起源的页岩中挤出并进入上方的某处砂岩或石灰岩体时，它们很容易迁移，因为砂岩（由石英颗粒组成）和石灰石（由碳酸盐矿物组成）比任何页岩都更具有渗透性。

When oil and gas are squeezed out of the shale in which they originated and enter a body of sandstone or limestone somewhere above, they migrate readily because sandstones (consisting of quartz grains) and limestones (consisting of carbonate minerals) are much more permeable than any shale.

油与石英或碳酸盐矿物之间的分子吸引力要弱于水与石英或碳酸盐矿物之间的分子吸引力。

The force of molecular attraction between oil and quartz or carbonate minerals is weaker than that between water and quartz or carbonate minerals.

因此，由于油和水不能混合，水仍然固定在石英或碳酸盐颗粒上，而油占据了多孔砂岩或石灰岩中较大开口的中心部分。

Hence, because oil and water do not mix, water remains fastened to the quartz or carbonate grains, while oil occupies the central parts of the larger openings in the porous sandstone or limestone.

因为石油比水轻，它倾向于向上穿过碳酸盐岩和石英岩所含的水。

Because oil is lighter than water, it tends to glide upward past the carbonate- and quartz-held water.

这样，油与水分离了。当遇到圈闭时，它可以形成一个池。

In this way, oil becomes segregated from the water; when it encounters a trap, it can form a pool.

在沉积物中形成的大部分石油找不到合适的圈闭，最终与地下水一起流向海洋表面。

Most of the petroleum that forms in sediments does not find a suitable trap and eventually makes its way, along with groundwater, to the surface of the sea.

据估计，最初埋在沉积物中的所有有机物，最终被困在油池中的比例不会超过0.1％。

It is estimated that no more than 0.1 percent of all the organic matter originally buried in a sediment is eventually trapped in an oil pool.

因此，毫不奇怪，在不超过250万年的岩石中发现了最高的油气池与沉积物体积的比率——足够年轻，几乎没有石油泄漏——而且到目前为止发现的所有石油和天然气中，有近60%是在过去6500万年形成的地层中发现的。

It is not surprising, therefore, that the highest ratio of oil and gas pools to volume of sediment is found in rock no older than 2.5 million years—young enough so that little of the petroleum has leaked away—and that nearly 60 percent of all oil and gas discovered so far has been found in strata that formed in the last 65 million years.

这并不意味着较老的岩石产生较少的石油。这仅表示较老岩石中的石油泄漏时间较长。

This does not mean that older rocks produced less petroleum; it simply means that oil in older rocks has had a longer time in which to leak away.

This is an extremely controversial question.

已经有数十亿桶石油被抽出地下。

Many billions of barrels of oil have already been pumped out of the ground.

通过钻探已经发现了很多额外的油，但仍在等待抽出。

A lot of additional oil has been located by drilling but is still waiting to be pumped out.

可能还有更多的石油有待钻探。

Possibly a great deal more oil remains to be found by drilling.

与数量可以准确估算的煤炭不同，未发现的石油的数量只能猜测。

Unlike coal, the volume of which can be accurately estimated, the volume of undiscovered oil can only be guessed at.

这些猜测涉及到使用一个世纪钻探中积累的经验。

Guesses involve the use of accumulated experience from a century of drilling.

了解到在钻探密集的地区（如德克萨斯州东部）发现了多少石油，专家们估计了其他岩石类型和结构与德克萨斯州东部类似的地区的可能储量。

Knowing how much oil has been found in an intensively drilled area, such as eastern Texas, experts make estimates of probable volumes in other regions where rock types and structures are similar to those in eastern Texas.

使用这种方法并考虑到世界上所有的沉积盆地，专家估计最终将发现1500到3万亿桶之间的石油。

Using this approach and considering all the sedimentary basins of the world, experts estimate that somewhere between 1,500 and 3,000 billion barrels of oil will eventually be discovered.

The word “trapped” in the passage is closest in meaning to

All of the following are cited in paragraph 2 as evidence that petroleum is a product of the decomposition of organic matter EXCEPT

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.

Why does the author include the information that “The force of molecular attraction between oil and quartz or carbonate minerals is weaker than that between water and quartz or carbonate minerals.”?

The word “suitable” in the passage is closest in meaning to

According to paragraph 4, what happens to most of the petroleum that forms in sediments?

The phrase “is an extremely controversial question” in the passage is closest in meaning to

According to paragraph 5, eastern Texas is an example of a geologic region where

Look at the four squares  that indicate where the following sentence could be added to the passage. Because such muds are a major source of petroleum, scientists believe that petroleum originated as living organisms.  Where would the sentence best fit? Click on a square  to add the sentence to the passage.

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 Origin of Petroleum Petroleum is defined as a gaseous, liquid, and semisolid naturally occurring substance that consists chiefly of hydrocarbons (chemical compounds of carbon and hydrogen). Petroleum is therefore a term that includes both oil and natural gas. Petroleum is nearly always found in marine sedimentary rocks. In the ocean, microscopic phytoplankton (tiny floating plants) and bacteria (simple, single-celled organisms) are the principal sources of organic matter that is trapped and buried in sediment. Most of the organic matter is buried in clay that is slowly converted to a fine-grained sedimentary rock known as shale. During this conversion, organic compounds are transformed to oil and natural gas. Sampling on the continental shelves and along the base of the continental slopes has shown that fine muds beneath the seafloor contain up to 8 percent organic matter.  Two additional kinds of evidence support the hypothesis that petroleum is a product of the decomposition of organic matter: oil possesses optical properties known only in hydrocarbons derived from organic matter, and oil contains nitrogen and certain compounds believed to originate only in living matter.  A complex sequence of chemical reactions is involved in converting the original solid organic matter to oil and gas, and additional chemical changes may occur in the oil and gas even after they have formed.  It is now well established that petroleum migrates through aquifers and can become trapped in reservoirs. Petroleum migration is analogous to groundwater migration. When oil and gas are squeezed out of the shale in which they originated and enter a body of sandstone or limestone somewhere above, they migrate readily because sandstones (consisting of quartz grains) and limestones (consisting of carbonate minerals) are much more permeable than any shale. The force of molecular attraction between oil and quartz or carbonate minerals is weaker than that between water and quartz or carbonate minerals. Hence, because oil and water do not mix, water remains fastened to the quartz or carbonate grains, while oil occupies the central parts of the larger openings in the porous sandstone or limestone. Because oil is lighter than water, it tends to glide upward past the carbonate- and quartz-held water. In this way, oil becomes segregated from the water; when it encounters a trap, it can form a pool. Most of the petroleum that forms in sediments does not find a suitable trap and eventually makes its way, along with groundwater, to the surface of the sea. It is estimated that no more than 0.1 percent of all the organic matter originally buried in a sediment is eventually trapped in an oil pool. It is not surprising, therefore, that the highest ratio of oil and gas pools to volume of sediment is found in rock no older than 2.5 million years—young enough so that little of the petroleum has leaked away—and that nearly 60 percent of all oil and gas discovered so far has been found in strata that formed in the last 65 million years. This does not mean that older rocks produced less petroleum; it simply means that oil in older rocks has had a longer time in which to leak away. How much oil is there in the world? This is an extremely controversial question. Many billions of barrels of oil have already been pumped out of the ground. A lot of additional oil has been located by drilling but is still waiting to be pumped out. Possibly a great deal more oil remains to be found by drilling. Unlike coal, the volume of which can be accurately estimated, the volume of undiscovered oil can only be guessed at. Guesses involve the use of accumulated experience from a century of drilling. Knowing how much oil has been found in an intensively drilled area, such as eastern Texas, experts make estimates of probable volumes in other regions where rock types and structures are similar to those in eastern Texas. Using this approach and considering all the sedimentary basins of the world, experts estimate that somewhere between 1,500 and 3,000 billion barrels of oil will eventually be discovered.