Now in some places of our country, many people are cutting down (砍 伐) the trees in the forests. They need more 1 to build houses and more farmland to grow crops and so on. The areas of forests are getting 2 . Some scientists say that there 3 no big forests in 20 or 30 years. It is really a(n) 4 thing. 5 the forests, we will have sandstorms(沙尘暴) often. The weather will get 6 . The earth will become a big desert(沙漠). A lot of plants and animals will 7 . Crops will not grow anywhere. Life will be 8 for everyone. So we should do our best 9 our living environment and keep our mountains 10 , the water clean, and the sky blue.