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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托福TPO作为托福的模考工具，它的题目对于我们备考托福很有参考价值，为了帮助大家备考，下面我给大家整理了托福TPO3阅读真题原文Part3，望喜欢！
托福TPO3阅读真题原文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阅读真题题目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阅读真题答案Part3
参考答案：
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阅读翻译Part3
参考翻译：生态系统的长期稳定
植物群体可以自由地聚集，它们特殊的结构取决于聚集区域的具体历史。生态学家使用"演替"来诠释植物群落和生态系统随着时间推移所发生的变化。演替中的第一个群落被称作先锋群落，而处于演替最后那个长期生存的群落被称为顶极群落。先锋群落和紧接着的植物群落的变化周期是从1到500年不等，植物数量和混合种类数量的变化是慢慢积累的。顶极群落本身也改变，但其变化周期超过500年。
现代一个研究池塘的生态学会发现池塘在一年当中相对而言是不变的。个别鱼类可能被替换，但年复一年鱼的总数都趋于一致。也就是说，一个生态系统自身的属性要比由单一生物体组成的生态系统更稳定。
生态学家们一度认为物种的多样性使生态系统稳定，生态系统物种越多样则生态系统越稳定。通过观察得出的结论支持了这个观点，长期持久的顶极群落通常要比先锋群落具备更为复杂的食物网和更多的物种。生态学家家们得出的结论是：顶点生态系统的稳定性明显取决于他们的复杂化程度。举个极端的例子，在单一作物的农田中，一年的恶劣天气或单一害虫的入侵就可以摧毁所有作物。与此相反，在一个复杂的顶极群落里，如温带森林，他们便可以抵御来自气候和害虫的干扰和入侵。
不管怎样，生态系统稳定性的问题非常复杂。首先，不是所有的生态学家都赞同"稳定"的含义。稳定性可以简单地定义为缺乏变化。如果是这样的话，顶极群落将被视为最稳定的，因为根据定义，他们随着时间推移而变化得最少。另外，稳定性也可以界定为生态系统在经历了严重破坏之后回复原貌的速度，比如火灾。这种稳定性也被称作弹性。在这种情况下，顶极群落将是最脆弱和最不稳定的，因为他们可能需要数百年时间才能恢复到顶点状态。
即使是这种被定义为简单地缺乏变化的稳定性并非总是与最多样的物种联系起来。至少在温带地区，会经常在演替过程中发现最多物种，而不是在顶极群落中。例如，红杉树林一旦成熟，其中的物种数量以及单个物种的数量都会减少。一般来说，多样性本身并不能保证稳定性(事实上正相反)，生态系统的数学模型也可以得出同样的结论。一个更复杂的系统可能比一个简单的系统更容易被破坏(一个十五速的 赛车 比一个孩子的三轮车更容易损坏)。
生态学家们更想弄清楚到底哪些因素有助于促成群落的恢复，因为世界各地的顶极群落都因为人类活动而遭受到严重的损坏或毁坏。就像美国西北部圣海伦火山的猛烈喷发所造成的破坏，在人类活动对环境造成的破坏面前也相形见绌。我们必须了解对群落抵抗、破坏和恢复来说哪些是最重要的。
现在的很多生态学家们认为，顶极群落相对长期的稳定性并非来自于多样性，而是来自环境的"补缀"，随处变化的环境比始终如一的环境更有利于多种有机体的生存。当地物种灭亡后，马上就会被相邻群落的移民取代。即便是另一种不同的物种，他们也可以填补那些已灭绝生物的空缺，并保持食物网的完整。
托福TPO3阅读真题原文及答案翻译Part3相关 文章 ：
1. 新托福阅读考试需要多长时间
托福TPO是托福备考小伙伴们最重要的参考资料，并且这个是在备考时候一定要认真多多练习，托福TPO是非常重要的希望大家一定要重视起来，我为广大的托福考生整理了托福阅读TPO10(试题+答案+译文)第1篇:Chinese Pottery，下面就来跟我一起来看下面精彩内容吧!
托福阅读原文
China has one of the world's oldestcontinuous civilizations—despite invasions and occasional foreign rule. Acountry as vast as China with so long-lasting a civilization has a complexsocial and visual history, within which pottery and porcelain play a majorrole.
The function and status of ceramics inChina varied from dynasty to dynasty, so they may be utilitarian, burial,trade-collectors', or even ritual objects, according to their quality and theera in which they were made. The ceramics fall into three broadtypes—earthenware, stoneware, and porcelain—for vessels, architectural itemssuch as roof tiles, and modeled objects and figures. In addition, there was animportant group of sculptures made for religious use, the majority of whichwere produced in earthenware.
The earliest ceramics were fired toearthenware temperatures, but as early as the fifteenth century B.C.,high-temperature stone wares were being made with glazed surfaces. During theSix Dynasties period (AD 265-589), kilns in north China were producinghigh-fired ceramics of good quality. White wares produced in Hebei and Henanprovinces from the seventh to the tenth centuries evolved into the highlyprized porcelains of the Song dynasty (AD. 960-1279), long regarded as one ofthe high points in the history of China's ceramic industry. The tradition ofreligious sculpture extends over most historical periods but is less clearlydelineated than that of stone wares or porcelains, for it embraces the oldcustom of earthenware burial ceramics with later religious images andarchitectural ornament. Ceramic products also include lead-glazed tomb modelsof the Han dynasty, three-color lead-glazed vessels and figures of the Tangdynasty, and Ming three-color temple ornaments, in which the motifs wereoutlined in a raised trail of slip—as well as the many burial ceramics producedin imitation of vessels made in materials of higher intrinsic value.
Trade between the West and the settled andprosperous Chinese dynasties introduced new forms and different technologies.One of the most far-reaching examples is the impact of the fine ninth-centuryAD. Chinese porcelain wares imported into the Arab world. So admired were thesepieces that they encouraged the development of earthenware made in imitation ofporcelain and instigated research into the method of their manufacture. Fromthe Middle East the Chinese acquired a blue pigment—a purified form of cobaltoxide unobtainable at that time in China—that contained only a low level ofmanganese. Cobalt ores found in China have a high manganese content, whichproduces a more muted blue-gray color. In the seventeenth century, the tradingactivities of the Dutch East India Company resulted in vast quantities ofdecorated Chinese porcelain being brought to Europe, which stimulated andinfluenced the work of a wide variety of wares, notably Delft. The Chinesethemselves adapted many specific vessel forms from the West, such as bottleswith long spouts, and designed a range of decorative patterns especially forthe European market.
Just as painted designs on Greek pots mayseem today to be purely decorative, whereas in fact they were carefully andprecisely worked out so that at the time, their meaning was clear, so it iswith Chinese pots. To twentieth-centuryeyes, Chinese pottery may appear merely decorative, yet to the Chinese the formof each object and its adornment had meaning and significance. The dragonrepresented the emperor, and the phoenix, the empress; the pomegranateindicated fertility, and a pair of fish, happiness; mandarin ducks stood forwedded bliss; the pine tree, peach, and crane are emblems of long life; and fishleaping from waves indicated success in the civil service examinations. onlywhen European decorative themes were introduced did these meanings becomeobscured or even lost.
From early times pots were used in bothreligious and secular contexts. The imperial court commissioned work and in theYuan dynasty (A.D. 1279-1368) an imperial ceramic factory was established atJingdezhen. Pots played an important part in some religious ceremonies. Longand often lyrical descriptions of the different types of ware exist that assistin classifying pots, although these sometimes confuse an already large andcomplicated picture.
托福阅读试题
1. The word “status” in thepassage(Paragraph 2)is closest in meaning to
A.origin
B. importance
C.quality
D.design
2.According to paragraph 2, which of thefollowing is true of Chinese ceramics?
A. The function of ceramics remained thesame from dynasty to dynasty.
B.The use of ceramics as trade objects isbetter documented than the use of ceramics as ritual objects.
C. There was little variation in qualityfor any type of ceramics over time.
D.Some religious sculptures were made usingthe earthenware type of ceramics.
3.The word “evolve” in the passage(Paragraph3)is closest in meaning to
A. divided
B.extended
C.developed
D. vanished
4.Which of the sentences below bestexpresses the essential information in the highlighted sentence(Paragraph 3) inthe passage? Incorrect choices change the meaning in important ways or leaveout essential information.
A.While stone wares and porcelains arefound throughout most historical periods, religious sculpture is limited to theancient period.
B.Religious sculpture was created in mostperiods, but its history is less clear than that of stone wares or porcelainsbecause some old forms continued to be used even when new ones were developed.
C.While stone wares and porcelains changedthroughout history, religious sculpture remained uniform in form and use.
D.The historical development of religioussculpture is relatively unclear because religious sculptures sometimes resembleearthenware architectural ornaments.
5.Paragraph 3 supports all of the followingconcerning the history of the ceramic industry in China EXCEPT:
A.The earliest high-fired ceramics were ofpoor quality.
B. Ceramics produced during the Tang andMing dynasties sometimes incorporated multiple colors.
Earthenware ceramics were produced in Chinabefore stone wares were.
D.The Song dynasty period was notable forthe production of high quality porcelain ceramics.
6.The word “instigate” in thepassage(Paragraph 4)is closest in meaning to
A.improved
B.investigated
C. narrowed
D.caused
7.According to paragraph 4, one consequenceof the trade of Chinese ceramics was
A. the transfer of a distinctive bluepigment from China to the Middle East
B.an immediate change from earthenwareproduction to porcelain production in European countries
C.Chinese production of wares made for theEuropean market
D.a decreased number of porcelain vesselsavailable on the European market
8.The word “whereas” in thepassage(Paragraph 5)is closest in meaning to
A. while
B. previously
C.surprisingly
D.because
9.In paragraph 5, the author compares thedesigns on Chinese pots to those on Greek pots in order to
A.emphasize that while Chinese pots weredecorative, Greek pots were functional
B.argue that the designs on Chinese potshad specific meanings and were not just decorative
C.argue that twentieth-century scholars arebetter able to understand these designs than were ancient scholars
D.explain how scholars have identified themeaning of specific images on Chinese pots
10.Which of the following is mentioned inparagraph 5 as being symbolically represented on Chinese ceramics?
A.Chinese rulers
B. love of homeland
C. loyally to friends
D. success in trade
11.Paragraph 5 suggests which of thefollowing about the decorations on Chinese pottery?
A.They had more importance for aristocratsthan for ordinary citizens.
B.Their significance may have remainedclear had the Chinese not come under foreign influence.
C.They contain some of the same images thatappear on Greek pots
D.Their significance is now as clear totwentieth century observers as it was to the early Chinese.
12.The word “these” in the passage(Paragraph6)refers to
A.religious ceremonies
B. descriptions
C.types of ware
D.pots
13. Look at the four squares [■]thatindicate where the following sentence could be added to the passage. Wherecould the sentence best fit? Foreign trade was also responsible for certaininnovations in coloring.
Trade between the West and the settled andprosperous Chinese dynasties introduced new forms and different technologies.One of the most far-reaching examples is the impact of the fine ninth-centuryAD. Chinese porcelain wares imported into the Arab world. ■【A】So admiredwere these pieces that they encouraged the development of earthenware made inimitation of porcelain and instigated research into the method of theirmanufacture. ■【B】From the Middle East the Chinese acquired a blue pigment—a purifiedform of cobalt oxide unobtainable at that time in China—thatcontained only a low level of manganese. Cobalt ores found in China have a highmanganese content, which produces a more muted blue-gray color. ■【C】In theseventeenth century, the trading activities of the Dutch East India Companyresulted in vast quantities of decorated Chinese porcelain being brought toEurope, which stimulated and influenced the work of a wide variety of wares,notably Delft. ■【D】The Chinese themselves adapted many specific vessel forms from theWest, such as bottles with long spouts, and designed a range of decorativepatterns especially for the European market.
14. Directions: An introductory sentencefor a brief summary of the passage is provided below. Complete the summary byselecting the THREE answer that express the most important ideas in thepassage. Some sentences do not belong in the summary because they express ideasthat not presented in the passage or are minor ideas in the passage. Thisquestion is worth 2 points.
Ceramics have been produced in China for avery long time.
A.The Chinese produced earthenware,stoneware, and porcelain pottery and they used their ceramics for a variety ofutilitarian, architectural, and ceremonial purposes.
B. The shape and decoration of ceramicsproduced for religious use in China were influenced by Chinese ceramicsproduced for export.
C.As a result of trade relations, Chineseceramic production changed and Chinese influenced the ceramics production ofother countries.
D. Chinese burial ceramics have the longestand most varied history of production and were frequently decorated withwritten texts that help scholars date them.
E.Before China had contact with the West,the meaning of various designs used to decorate Chinese ceramics was wellunderstood.
F.Ceramics made in imperial factories wereused in both religious and non-religious contexts.
托福 阅读答案
1.status状态，地位，所以B的importance重要性，地位正确。原句说瓷器的作用和什么因朝代而不同，而且之后有解释可能是实用的，用于埋葬的，或者blabla，所以importance能对上。origin起源不可能因为朝代而变化;quality后面有，不应该重复;design与后文的例子对不上
2.问题中的关键词不能用，所以排除法最好。A的dynasty todynasty做关键词定位至第一句，说反，错;B的trade objects和ritual objects做关键词定位至第一句，原文没有比较，错;C的quality做关键词定位至第一句，说根据它们质量决定用来干嘛，所以质量是有变化的，C错;D的religious和earthenware做关键词定位至最后一句，正确
3.evolve进化，演化，所以C的develop正确。原文说七到十世纪的白瓷怎么样成了宋代的很好的瓷，无论从时间上还是后面说的highly prized都证明后面的比前面的好，所以应该是变好的意思，A分开B延伸D消失都没有变好之意
4.原文的主要关系是因果，因果的结果部分包含了一个转折，所以从结构上说只有B和D可能正确。B正确，D错在原文说stoneware和porcelain比religious sculpture清楚，但没说religious sculpture不清楚，错
5.EXCEPT题，排除法。A的high-firedceramics做关键词定位至第二句，原文说good quality, 备选项说poor，反了，错，选;B的Tang and Ming Dynasty做关键词定位至最后一句，正确，不选;C的earthenware和stoneware做关键词定位至第一句，原文说最早的是earthenware，所以比stoneware早，所以C正确，不选;D的Song dynasty做关键词定位至第三句，正确，不选
6.nstigate教唆，鼓动，煽动，所以cause引起正确，注意不要被investigate迷惑。原句说那些陶器非常惹人喜爱，促进了earthenware的发展，也instigate了制陶 方法 的研究，instigate与原文的encourage并列，所以应该是鼓励之意。A提升改善B调查C变窄均不正确
7.以trade of Chineseceramics做关键词定位至倒数第二句，问结果，所以应该关注result in之后的内容，说大量的Chinese porcelain到了欧洲，影响了一系列ware，接着又说会专门为欧洲市场做一些ware，所以C正确;注意B尽管说到了change，但immediate是原文没说的;A没说;D说反了，应该是增加
8.注意 句子 中的seem和in fact，seem叫做看上去，也就是事实很可能不是这样，后面的in fact叫做事实上，也就是说前面说的很可能不是事实，两者呼应，都说明两句话之间的关系是转折，所以while正确
9.先看本句，现代人认为希腊的pots上的design只是装饰，没有实际意义，但事实上是有意义的，中国的pots也这样，所以B正确。A错，不是pots decorative，而是design;C说反，D没说方式，所以how错
10.问下面哪个是design的替代意义，倒数第二句整个都在说pots上design的意义，提到了emperor和empress，皇帝和皇后，所以A的Chinese rulers正确，统治者;其他都没说
11.问题中关键词不明显，排除法。A的ordinarycitizens和aristocrat原文没说;B的foreign influence做关键词定位至最后一句的European，说直到引入欧洲theme之后中国原有的装饰的意思才被obscure，对应B，没有foreign influence那些意思不会改变，正确;C没说;D反了，应该是ancient更熟悉
12.these往前找，找主语。注意从句子一开始到exist之前都是句子的主语，但of之前的东西是整个句子的核心，所以答案是description，对于什么什么的描述，描述才是核心，不是types of ware
13.两个过渡点，名词foreign trade和coloring。foreigntrade对应原文第四句的from Middle East Chinese acquired blabla和倒数第二句的tradingactivities，所以B/C/D都有可能;coloring证明B或者C正确。按照正常逻辑，应该先总括，说外贸也使染色技术发生变化，接着再说怎么变的，所以B正确，C错误
14.The Chinese选项对应第二段第二句，正确
The shape选项原文没说，不选
As选项对应原文第四段第一句，正确
Chinese选项原文没说，不选
Before选项对应原文第五段最后一句，正确
Ceramics选项MS对应原文最后一段，但最后一段没说imperial陶瓷是用于both情况的，也不选
托福阅读译文
【1】尽管中国曾饱受入侵，偶尔丧失主权受制于外国，她仍然拥有世界上最源远流长的文明。像中国一个拥有悠久文明的大国，而陶瓷在其复杂的社会历史以及视觉历史中扮演了极为重要的角色。
【2】在中国，每一个朝代陶瓷的功能和地位都是不同的，所以，根据它们的质量和制作年代的不同，可以是实用器物、陪葬品、贸易 收藏 品，甚至是礼器。对于容器、瓦片等建筑材料、模仿的物体或人物，陶瓷广义上被分为3大类：陶器、炻器和瓷器。另外，瓷器中还有很重要的一类就是宗教用途的雕塑，它们多数是陶质的。
【3】尽管最早的陶瓷是在制陶的温度下烧制的，但是早在公元前15世纪，就已经出现了上釉的高温炻器。六朝时期(公元265-589年)，中国北方就有窑炉在烧制优质的高温瓷器。从7世纪到10世纪，河北以及河南省产的白瓷逐渐演变成为享有盛名的宋瓷(公元960-1279年)——长久以来被认为是中国陶瓷业历史中的巅峰时期之一。宗教雕塑的传统在大部分历史时期中都有延续，但是没有炻器和瓷器质地的雕塑描绘的那么清晰，有一种古老的习俗，就是将刻着新的宗教形象和建筑装饰的陶器作为陪葬品。瓷制品还包括汉朝的铅釉随葬陶俑，唐朝的三彩铅釉器皿和人物，明朝的以泥釉凸纹展现轮廓的三彩寺庙装饰物以及很多用来仿制贵重器皿的陪葬瓷器。
【4】西方国家和繁荣稳定的历代中国朝代之间的贸易促使双方互相引入了新的形式和不同的技术。有一个意义最为深远的例子，公元9世纪精美中国瓷器出口到阿拉伯世界，带来巨大的影响。阿拉伯人对这些瓷器赞不绝口，于是他们鼓励制陶来仿制瓷器，并激励人们研究制作方法。中国人从中东获得了一种蓝色颜料——一种纯化的氧化钴，当时在中国并未出现，其中只含有少量的锰。中国境内发现的钴矿石含有大量的会产生暗蓝灰色的锰元素。17世纪，大量中国装饰类瓷器通过荷兰东印度公司的交易活动流入欧洲，这刺激和影响了广泛多样的瓷器的生产，特别是代尔夫特 。中国人自己改良了很多种来自西方的特殊器皿，比如长嘴的瓶子，并专门为欧洲市场设计了一系列装饰性图案。
【5】就像希腊的陶器上所绘的图案，今天看来也许纯粹是为了装饰，然而事实上在当时它们都是人们精心烧制而成的，它们的意义在当时非常明确，中国的瓷器也是如此。以20世纪的眼光来看，中国制造的陶瓷也许仅仅是装饰品，但是对于中国人来说每个物件的形状及它的装饰都有寓意非凡，影响深远。龙代表皇帝，凤代表皇后;石榴意味着多子，双鱼意味着幸福;鸳鸯寓意着婚姻幸福美满;松树、桃树以及鹤都是长寿的象征;鱼跃出水面意味着科举考试会高中。但是欧洲的装饰主题被引进后，这些寓意就变得不再那么流行甚至丢失了。
【6】陶瓷器皿在很早期就已用于宗教和日常生活中。朝廷分派了制作工作，并于元朝(公元1279-1368年)在景德镇设立了一座官窑。陶瓷器皿在一些宗教仪式上也有着重要的地位。现存的关于不同类型的陶瓷器具很多长篇且抒情的描述可以帮助我们对其进行分类，尽管这些描述有时候会使得一幅大而复杂的画面显得凌乱。
托福阅读TPO10(试题+答案+译文)第1篇:Chinese Pottery相关 文章 ：
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TPO7(试题+答案+译文)第1篇:The Geologic History of the Mediterranean。
托福阅读原文
In 1970 geologists Kenneth J.Hsu and William B.F. Ryan were collecting research data while aboard the oceanographicresearch vessel Glomar Challenger.Anobjective of this particular cruise wasto investigate the floor of theMediterranean and to resolve questions aboutits geologic history. One questionwas related to evidence that theinvertebrate fauna (animals without spines) ofthe Mediterranean had changedabruptly about 6 million years ago. Most of theolder organisms were nearlywiped out, although a few hardy species survived. Afew managed to migrate into the Atlantic.Somewhat later, the migrants returned,bringing new species with them. Why didthe near extinction and migrationsoccur?
Another task for the GlomarChallenger’sscientists was to try to determine the origin of the domelikemasses buried deepbeneath the Mediterranean seafloor. These structures had beendetected yearsearlier by echo-sounding instruments, but they had never beenpenetrated in thecourse of drilling. Were they salt domes such as are commonalong the UnitedStates Gulf Coast, and if so, why should there have been somuch solidcrystalline salt beneath the floor of the Mediterranean?
With question such as these clearly beforethem, thescientists aboard the Glomar Challenger processed to the Mediterraneantosearch for the answers. On August 23, 1970, they recovered a sample. Thesampleconsisted of pebbles of hardened sediment that had once been soft,deep-seamud, as well as granules of gypsum and fragments of volcanic rock. Nota singlepebble was found that might have indicated that the pebbles came fromthenearby continent. In the days following, samples of solid gypsumwererepeatedly brought on deck as drilling operations penetrated theseafloor.Furthermore, the gypsum was found to possess peculiarities ofcomposition andstructure that suggested it had formed on desert flats. Sedimentabove andbelow the gypsum layer contained tiny marine fossils, indicatingopen-oceanconditions. As they drilled into the central and deepest part oftheMediterranean basin, the scientists took solid, shiny, crystalline saltfromthe core barrel. Interbedded with the salt were thin layers of whatappeared tobe windblown silt.
The time had come to formulate ahypothesis. The investigators theorized that about 20 million years ago, theMediterranean wasa broad seaway linked to the Atlantic by two narrow straits.Crustal movements closedthe straits, and the landlocked Mediterranean began toevaporate. Increasingsalinity caused by the evaporation resulted in theextermination of scores ofinvertebrate species. only a few organisms especiallytolerant of very saltyconditions remained. As evaporation continued, the remainingbrine (salt water)became so dense that the calcium sulfate of the hard layerwas precipitated. Inthe central deeper part of the basin, the last of the brineevaporated toprecipitate more soluble sodium chloride (salt). Later, under theweight ofoverlying sediments, this salt flowed plastically upward to form saltdomes.Before this happened, however, the Mediterranean was a vast desert 3,000metersdeep. Then, about 5.5 million years ago came the deluge. As a result ofcrustaladjustments and faulting, the Strait of Gibraltar, where theMediterranean nowconnects to the Atlantic, opened, and water cascadedspectacularly back intothe Mediterranean.Turbulent waters tore into thehardened salt flats, brokethem up, and ground them into the pebbles observed inthe first sample taken bythe Challenger. As the basin was refilled, normalmarine organisms returned.Soon layer of oceanic ooze began to accumulate abovethe old hard layer.
Thesalt and gypsum, the faunal changes, and the unusualgravel provided abundantevidence that the Mediterranean was once a desert.
托福阅读试题
1.The word “objective”in the passage(paragraph 1) is closest in meaning to
A.achievement
B.requirement
C.purpose
D.feature
2.Which of the following is NOT mentionedin paragraph 1 as a change thatoccurred in the fauna of the Mediterranean?
A.Most invertebrate species disappearedduring a wave of extinctions.
B.A few hardy species wiped out many of theMediterranean’s invertebrates.
C.Some invertebrates migrated to AtlanticOcean.
D.New species of fauna populated theMediterranean when the old migrants returned.
3.1.Whatdoes the author imply by saying“Not a single pebble was found that might have indicated that the
pebbles came from the nearby continent”?(paragraph 3)
A.The most obvious explanation for theorigin of the pebbles was not supported by the evidence.
B.The geologists did not find as manypebbles as they expected.
C.The geologists were looking for aparticular kind of pebble.
D.The different pebbles could not have comefrom only one source.
4.Which of the following can be inferredfrom paragraph 3 about the solidgypsum layer?
A.It did not contain any marine fossil.
B.It had formed in open-ocean conditions.
C.It had once been soft, deep-sea mud.
D.It contained sediment from nearbydeserts.
5.Select the TWO answer choice from paragraph3 that identify materialsdiscovered in the deepest part of the Mediterraneanbasin. To receive credityou must select TWO answers.
A.Volcanic rock fragments
B.Thin silt layers
C.Soft, deep-sea mud
D.Crystalline salt
6.What is the main purpose of paragraph 3?
A.To describe the physical evidencecollected by Hsu and Ryan
B.To explain why some of the questionsposed earlier in the passage could not be answered by the findings of theGlomar Challenger
C.To evaluate techniques used by Hsu andRyan to explore the sea floor
D.To describe the most difficult problemsfaced by the Glomar Challenger expedition
7.According to paragraph 4, which of thefollowing was responsible for theevaporation of the Mediterranean’s waters?
A.The movements of Earth’s crust
B.The accumulation of sediment layers
C.Changes in the water level of theAtlantic Ocean
D.Changes in Earth’s temperature
8.The word “scores”in the passage(paragraph 4) is closest in meaning to
A.members
B.large numbers
C.populations
D.different types
9.According to paragraph 4, what causedmost invertebrate species in theMediterranean to become extinct?
A.The evaporation of chemicals necessaryfor their survival
B.Crustal movements that connected theMediterranean to the saltier Atlantic
C.The migration of new species through thenarrow straits
D.Their inability to tolerate theincreasing salt content of the Mediterranean
10.Which of the sentences below bestexpresses the essential information inthe highlighted sentence in the passage(paragraph 4) ? Incorrect choices change the meaning inimportant ways or leaveout essential information.
A.The strait of Gibraltar reopened when theMediterranean and the Atlantic became connected and the cascades of water fromone sea to the other caused crustal adjustments and faulting.
B.The Mediterranean was dramaticallyrefilled by water from the Atlantic when crustal adjustments and faultingopened the Strait of Gibraltar, the place where the two seas are joined.
C.The cascades of water from the Atlanticto the Mediterranean were not as spectacular as the crustal adjustments andfaulting that occurred when the Strait of Gibraltar was connected to thoseseas.
D.As a result of crustal adjustments andfaulting and the creation of the Strait of Gibraltar, the Atlantic andMediterranean were connected and became a single sea with spectacular cascadesof water between them.
11.The word “Turbulent”in the passage(paragraph 4) is closest in meaning to
A.Fresh
B.Deep
C.Violent
D.Temperate
12. Look at the four squares [■] thatindicate where the following sentence could be added to the passage. Thus,scientists had information about the shape of the domes but not about theirchemical composition and origin.
■【A】Another task for theGlomar Challenger’s scientists was totry to determine the origin of thedomelike masses buried deep beneath theMediterranean seafloor. ■【B】These structures had been detected years earlierby echo-soundinginstruments, but they had never been penetrated in the courseof drilling. ■【C】Were theysalt domes such as are common alongthe United States Gulf Coast, and if so, whyshould there have been so muchsolid crystalline salt beneath the floor of theMediterranean? ■[D】
Where would the sentence best fit?
13. Direction: An introductory sentence fora brief summary of the passage is provided below. Complete the summary byselecting the THREE answer choices that express the most important ideas in thepassage. Some sentences do not belong in the summary because they express ideasthat are not presented in the passage or are minor ideas in the passage. Thisquestion is worth 2 points.
An expedition to the Mediterranean answeredsome long-standing questionsabout the ocean’s history.
A.The Glomar Challenger expeditioninvestigated changes in invertebrate fauna and some unusual geologic features.
B.Researchers collected fossils todetermine which new species migrated from the Atlantic with older species.
C.Scientists aboard the Glomar Challengerwere the first to discover the existence of domelike masses underneath theseafloor.
D.Samples recovered from the expeditionrevealed important differences in chemical composition and fossil distributionamong the sediment layers.
E.Evidence collected by the GlomarChallenger supports geologists' beliefs that the Mediterranean had evaporatedand become a desert, before it refilled with water.
F.Mediterraneansalt domes formed after crustal movements opened the straits between theMediterranean and the Atlantic, and the Mediterranean refilled with water.
托福 阅读答案
1.C
2.文第四句话说到“Most of theolder organisms were nearly wiped out(大部分更加古老的生物都几乎灭绝了)”对应选项A;第五句说到“A few managed to migrate into the Atlantic(一些物种成功地迁移到了大西洋)”，对应选项C;第六句说到“the migrants returned, bringing new species with them(这些物种又回到了地中海，并带回新的物种)”，对应选项D。第一段中没有提到B 选项，故答案是B选项。
3.推理题考察的是文中没有明确说到的内容，需要经过推理。选项B、C、D在文中均没有任何线索体现。对于选项A，如果我们在阅读 文章 时，能够比较好的关注上下文，我们会发现：在原文之中第二段，文中提及“它们是像美国海湾海岸一带的含盐圆顶状巨块" ---美国海湾的东西怎么会突然出现在了地中海区域?于是对于这些地中海的大巨块，最简单的解释是他们来自美洲湾。既然第二段提出了问题，第三段做出相应的回答，因此第三段的内容应该与第二段的问题是有联系的，支持或者反对。而现在的这句话(“在被发现的样品中，没有一个表明这些细砾来自于邻近的大陆”)，当然打破了这个最为明显的可能解释---关于巨大的块儿起源的解释。
4.A
5.BD
6.A
7.A
8.原文该单词所在 句子 为:"Increasingsalinity caused by the evaporation resulted in the extermination of scores ofinvertebrate species." 可以理解为: "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。"
Score是得分的意思，在球类比赛中经常可以听到，可以根据the extermination of scores of invertebrate species这个结构判断出scores表示数量的意思，对应选项B(这个还是记住吧)
9.D
10.B
11.C
12.C
13.选项A是正确的，是第一二段的内容
选项B是错误的，是文章未提及的内容
选项C是错位的，与第二段第二句内容相反
选项D是正确的，是第四段的内容
选项E是正确的，是文章最后一段的内容
选项F是错误的，与第四段内容不符，是地壳运动和断层作用打开了地中海和大西洋之间的海峡，并非盐穹(应该说domes在此之前就形成了)
托福阅读原文
【1】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?
【2】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?
【3】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。
【4】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。
【5】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。
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