题目内容：

阅读与回答问题

1970 was “World Conservation(保护) Year”. The United Nations wanted everyone to know that the world is at risk(危险).They hoped that people would do something quickly to conserve nature.

Here is one example of the problem. At one time there were 1,300 plants, trees and flowers in Holland, but now only 860 are existing. The others have been destroyed by modern man and his technology.

Here is another example. In 1620, about half the USA was covered by forests. In 1850, about a third was covered by forests. Today the forests have almost gone. A lot of good land has gone with them, leaving only sand. Today too many trees are still being cut down.

We’re changing the earth, the air and water. We can’t live without these things. If we go on like this, we shall destroy ourselves. A lot of people know that conservation is necessary. Many things have been done to save our world. For example, people plant more and more trees on the hills. In a small town in the USA a large group of girls cleaned the banks of 11 kilometers of their river. Young people may hear about conservation through a record by the name of NO ONE’S GOING TO CHANGE OUR WORLD. It was made by Scales, Cliff Richard and other singers. The money from it will help to conserve wild plants and animals. In China, a new Great Wall has been built across the northern part of the country to stop the sand from moving towards the rich farmland in the south.

1.What year was 1970?

______________________________________________________________

2.What did the United Nations hope ?

______________________________________________________________

3.How much land in the USA is covered by forests in 1850?

______________________________________________________________

4.Can you give us an example that people have done to save our world?

______________________________________________________________

5.What has a new Great Wall been built for?

______________________________________________________________