阅读下列短文，从每题所给的A、B、C、D四个选项中选出最佳选项。
A
Animals are natural resources that people have wasted all through our history. Animals have been killed for their fur and feathers, for food, for sport, and simply because they were in the way. Thousands of kinds of animals have disappeared from the world forever. Hundreds more are on the danger list today. About 170 kinds in the United States alone are considered in danger.
Why should people care? Because we need animals. And because once they are gone, there will never be any more.
Animals are more than just beautiful and interesting. They are more than just a source of food. Every animal has its place in the balance of nature. Destroying one kind of animal can create many problems.
For example, when farmers killed large numbers of hawks(老鹰), the farmers stores of corn and grain were destroyed by rats and mice. Why? Because hawks eat rats and mice. With no hawks to keep down their numbers, the rats and mice multiplied quickly.
Luckily, some people are working to help save the animals. Some groups raise money to let people know about the problem. And they try to get the governments to pass laws protecting animals in danger.
Quite a few countries have passed laws. These laws forbid(禁止)the killing of any animals or plants on the danger list. Slowly, the number of some animals in danger is growing.
21.What is the best title for the passage?
A. Useful Animals B. Save the Animals
C. Laws for Animals D. Animals in Danger
22. Animals are important to us mainly because ________.
A. they give us a source of food B. they are beautiful and lovely
C. they keep the balance of nature D. they give us a lot of pleasure
23. What is the meaning of the underlined word “multiplied” in the passage?
A. Became less B. Became more
C. Turned black D. Ate food
24. We can infer from the passage that ________.
A. people have known the importance of animal protection a long time ago
B. the number of hawks is on the decrease
C. many countries passed laws forbidding the killing of any animal
D. animals play an important role in people’s life
