問題詳情

DThe African elephant, the largest land animal remaining on earth , is of great importanceto African ecosystem(生态系统). Unlike other animals, the African elephant is to a greatextent the builder of its environment. Aa big plant-eater, it largely shapes theforest-and-savanna(大草原)surroundings in which it lives, therefore setting the termsof existence for millions of other animals that live in its habitat(栖息地).It is the elephant's great desire for food that makes it a disturber of the environmentand an important builder of its habitat. In its continuous search for the 300 pounds ofplants it must have every day, it kills small trees and underbushes, and pulls branchesoff big trees. This results in numerous open spaces in both deep tropical forests and in the woodlands that cover part ofthe African savannas. In these open spaces are numerous plants in various stages of growth that attract a variety of other plant-eaters.Take the rain forests for example. In their natural state, the spreading branches overhead shutout sunlight and prevent the growth of plants on the forest floor. Bpulling down trees andeating plants, elephants make open spaces, allowing new plants to grow on the forest floor.In such situations, the forests become suitable for large hoofed plant-eaters to move aroundand for small plant-eaters to get their food as well.What worries scientists now is that the African elephant has become an endangeredspecies. If the elephant disappears, scientists say, many other animals will also disappearfrom vast areas of forest and savanna, greatly changing and worsening the whole ecosystem.
67.What is the passage mainly about?
(A)Disappearance of African elephants.
(B)Forests and savannas as habitats for African elephants.
(C)The effect of African elephants' search for food.
(D)The eating habit of African elephants.

參考答案

答案：C
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)

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