题目内容
The African elephant,the largest land animal remaining on the earth,is of great importance to African ecosystem (生态系统) .Unlike other animals,the African ele?phant is to a great extent the builder of its environment. As a big planteater,it largely shapes the forest and sa?vanna(稀树草原) surroundings in which it lives,therefore setting the terms of existence for millions of other animals that live in its habitat (柄息地) .
It is the elephant's great desire for food that makes it a disturber of the environment and an important builder of its habitat. In its continuous search for the300 pounds of plants it must have every day,it kills small trees and underbushes,and pulls branches off big trees. This results in numerous open spaces in both deep tropical forests and in the woodlands that cover part of the African savannas. In these open spaces are numerous plants in various stages of growth that attract a variety of other planteaters.
Take the rainforests for example. In their natural state,the spreading branches overhead shut out sunlight and prevent the growth of plants on the forest floor. By pulling down trees and eating plants,elephants make open spaces,allowing new plants to grow on the forest floor. In such situations,the forests become suitable for large hoofed planteaters to move around and for small planteaters to get their food as well.
What worries scientists now is that the African ele?phant has become an endangered species. If the elephant disappears,scientists say,many other animals will also disappear from vast areas of forest and savanna,greatlychanging and worsening the whole ecosystem.
14. What is the passage mainly about?
A. Disappearance of African elephants.
B. Forests and savannas as habitats for African ele?phants.
C. The effect of African elephants' search for food.
D. The eating habit of African elephants.
15. What does the underlined phrase" setting the terms" most probably mean?
A. Fixing the time.
B. Worsening the state.
C. Improving the quality.
D. Deciding the conditions.
16. What do we know about the open spaces in the passage?
A. They result from the destruction of rainforests.
B. They provide food mainly for African elephants.
C. They are home to many endangered animals.
D. They are attractive to planteating animals of dif?ferent kinds.
17. The passage is developed mainly by .
A. showing the effect and then explaining the causes
B. pointing out similarities and differences
C. describing the changes in space order
D. giving examples
[文章大意]本文主要讲述的是在非洲草原的生物链中大象所起的重要作用。它不断地寻找食物从而拓宽了其他动物的生存空间。
14. C主旨大意题。本文主要讲述的就是在非洲草原的生物链中大象所起的重要作用。它不断地寻找食物从而拓宽了其他动物的生存空间。故C正确。
15. D短语猜测题。根据文章第一段中的"As a big plant-eat-er,it largely shapes the forest and savanna (稀树草原) sur?roundings in which it lives,therefore setting the terms of ex?istence for millions of other animals that live in its habitat (栖息地) ."可知，非洲大象塑造了草原的环境，也决定了其他动物的生存条件。故D项正确。
16. D细节理解题。根据文章第二段的最后一句可知，这种空地中的各种植物吸引了多种食草动物。故D项正确。
17. A文章结构题。本文的行文结构是这样的：先向读者展示出一种现象或结果，再具体来解释造成这种现象或结果的原因。故A正确。
