2010年中国人民大学考博英语真题4

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Passage Three

Who would have thought we would become a planet of “ologies”？ There’s biology, psychology, herpetology, etymology, and geology just to name a few. However, one “ology” truly helps us to understand the most part of our planet, our environment. Ecology (which is filled with ecologists) is the study of ecosystems and the beings and organisms that inhabit those ecosystems. Just think, in condition of bees, deer and other organisms, you are important to ecologists. Ecosystems are communities that vary in size and location. They can be as small as a patch of glass or as large as the entire biosphere. The many varieties of plants and animals that exist in our planet ecosystems are important to our ecosystems. Plants in particular provide oxygen and nutrients all organisms need to survive. These producers have the ability to use the sun’s energy to produce food

(think photosynthesis). This is where the animals and consumers become important. The animals get their energy by eating the plants and other organisms within the ecosystem. Without the producers and consumers, decomposers would not have a job. As you may have guests, decomposers, like bacteria, step in broken down, the organic materials are absorbed by the soil and gases are sent back into our atmosphere. The whole process is ready to start again through the Earth’s natural cycles. There has to be a balance of producers, consumers, decomposers in order to remain a balanced ecosystem.

Remember, all organisms need matter and energy to survive. An ecosystem is balanced when matter and energy move efficiently through those ecosystems. Just as your backpack has a limit on the number of huge textbooks it can carry at any given time, all ecosystems have a limit on the populations they can maintain. Carrying capacity is the largest population an ecosystem can support at any particular time. The support of this population depends on the amount of resources (matter and energy) that are available and the movement of those resources within that ecosystem. If energy and matter are moving efficiently through an ecosystem, then the current population of plants and animals has not reached beyond the ecosystem’s the ecosystem’s carrying capacity. Once resources dwindle or animal populations increase dramatically, the ecosystem may not be able to support those populations. Fortunately, nature has three ways to control the balance of ecosystems: ecological responses to change, energy transfer, and food chains and food webs.

31. The purpose of starting the article with the word-ending “ology” ( Line 1, Paragraph 1) is

A. to trace the origin of “ology”

B. to give an example for the meaning of “ology”

C. to introduce the term “ecology”

D. to illustrate the importance of balancing the ecosystems

32. According to this article, the ecosystems .

A. are in danger of being destroyed B. are very small in size

C. refer only to the entire biosphere D. vary greatly in size and location

33. According to the article, the word “producers”(Line 4，Paragraph 2) refers to •

A. plants B. animals C. ecologists D. consumers

34. We can infer from the article that in the ecosystem the job for the “decomposer”( Lines 7-8, Paragraph 2) is to •

A. absorb the sun’s energy

B. produce oxygen and nutrients

C. break down the dung and the remains of dead organ

D. eat the plants and animals

35. According to the article, has three ways to control the balance of the ecosystems.

A. human beings B. the environment C. animals and plants D. nature

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