D
The African elephant, the largest land animal remaining on earth , is of great importance
to African ecosystem(生态系统). Unlike other animals, the African elephant is to a great
extent the builder of its environment. Aa big plant-eater, it largely shapes the
forest-and-savanna(大草原)surroundings in which it lives, therefore setting the terms
of 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 environment
and an important builder of its habitat. In its continuous search for the 300 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 plant-eaters.
Take the rain forests for example. In their natural state, the spreading branches overhead shut
out sunlight and prevent the growth of plants on the forest floor. Bpulling 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 plant-eaters to move around
and for small plant-eaters to get their food as well.
What worries scientists now is that the African elephant has become an endangered
species. If the elephant disappears, scientists say, many other animals will also disappear
from vast areas of forest and savanna, greatly changing and worsening the whole ecosystem.
【題組】69. What do we know about the open spaces in the passage?
(A)They result from the destruction of rain forests.
(B)They provide food mainly for African elephants.
(C)They are home to many endangered animals.
(D)They are attractive to plant-eating animals of different kinds.