阅读短文,从A、B、C、D四个选项中选出可以填入空白处的正确答案。
Today we can see that many people are cutting down the trees in the forests. A lot of1lands have become deserts. If we read newspapers, we'll learn that the forests on the earth are getting smaller2. We are cutting down large numbers of trees3we need wood and farmland. Some scientists say that there will not be any great forests420 or 30 years.
What will happen if the forests disappear? A lot of plants will die and the animals will5their homes. In many places the new farmland will soon look6the old desert. Crops will not grow there. There won't be enough7, and the weather will get hot and dry. If the climate of the earth changes, life will be8for everyone. Our living environment will become9. More and more rich farmland will disappear. We will suffer a lot from both droughts (干旱) and floods.
It's our duty10the forests well. Everyone should try his best to make a contribution (贡献) to taking care of the forests. Stop cutting down the trees and make the world greener!