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 earth 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 or 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, 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 the killing of any animal or plant on the danger list. Slowly, the number of some animals in danger is growing.
There are a lot of useful animal, such as dragonflies, frogs and so on.
我们先说蜻蜓吧，它是益虫，它对人的`益处可多了。它生活在小池子旁边，捕捉害虫。有些人，捉蜻蜓，捕蜻蜓，捉住后到处卖。我们应给 ...... 阅读全文