阅读下面短文，掌握其大意，然后从各题所给的A,B,C,D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 1 in Hong Kong, these trees were cut down and burnt. Now there is 2 forest left, though there are still some small areas covered with trees. We call these woods, not forests.
Elephants,tigers and many 3 animals were living in the thick forest. When people came to live in Hong Kong, the 4 began to die out. Early farmers grew rice and kept pigs and chickens in the valleys (山谷). They cut down the trees and burnt them. They needed fire to keep themselves 5 in winter, to cook their food and to keep away the dangerous animals. Elephants 6 disappeared because there was not enough food for them. So did most of the wolves and tigers. Monkeys and many other animals soon died 7 the same way.
You might think that there are no longer any animals in Hong Kong except in the zoos. There 8 still about 36 different animals living there. One of the most interesting of Hong Kong's animals is the barking deer (麂). These are beautiful little animals with a rich brown coat and a white patch(补丁) under the tail. They look like deer but they are much smaller. They are less than two feet 9 . They make a noise rather like a dog barking. In Hong Kong the barking deer has only one real enemy – 10 . People hunt these little animals though it is illegal (违法的). There are now not many barking deer left. So it is important for people to protect wild animals.
