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 in trees．We call these woods.
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 5 pigs and chickens in the valleys. They cut down the trees and burnt them. They needed 6 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.  7 did most of the wolves and tigers. Monkeys and many other animals soon 8 in the same way.
You might think that there are no longer any animals in Hong Kong 9 in the zoos. But there are still about 36 different animals 10 there. One of the most interesting of Hong Kong's animals is the barking deer.

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.
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 　5　 pigs and chickens in the valleys. They cut down the trees and burnt them. They needed 　6　 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. So did 　7　 of the wolves and tigers. Monkeys and many other animals soon 　8　 in the same way.
You might think that there are no longer any animals in Hong Kong 　9　 in the zoos. But there are still about 36 different animals 　10　 there. One of the most interesting of Hong Kong's animals is the barking deer. These are beautiful little animals 　11　 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（英尺） 　12　. They make a noise rather like a dog 　13　. In Hong Kong the barking deer has only a real enemy--　14　. People hunt these little animals though it is illegal (违法的). There are now not many barking deer left. So it is important 　15　 people to protect wild animals.

_____ trees were cut down. And many birds lost their home.

A. Two thousands    B. Thousands of   D. Thousand of