通读下面的短文，掌握其大意。然后，从每小题的四个选项中选出最佳选项。 　　A thousand years ago, Hong Kong was covered by a thick forest. ...

通读下面的短文，掌握其大意。然后，从每小题的四个选项中选出最佳选项。
　　A thousand years ago, Hong Kong was covered by a thick forest. As more and more people came to　21　in Hong Kong, these trees were cut down and burnt. Now there is　22　forest left, though there are still some small areas covered with trees. We call these woods.
　　Elephants, tigers and many　23　animals were living in the thick forest. When people came to live in Hong Kong, the　24　began to die out. Early farmers grew rice and　25　pigs and chickens in the valleys. They cut down the trees and burnt them. They needed　26　to keep themselves warm in winter, to cook their food and to keep away the dangerous animals. Elephants quickly disappeared because there was not enough food for them.　27　did most of the wolves and tigers. Monkeys and many other animals soon　28　in the same way.
　　You might think that there are no longer any animals in Hong Kong　29　in the zoos. There are still about 36 different animals　30　there. One of the most interesting of Hong Kong’s animals is the barking deer. These are beautiful little animals　31　a rich brown coat and a white patch under the tail. They look like deer　32　but they are much like a dog　33　. In Hong Kong the barking deer has only a real enemy－34　. People hunt these little animals though it is illegal. There are now not many barking deer left. So it is important　35　people to protect wild animals.
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