补全对话。(每空一词,共5分) A: What bad weather! Another sandstorm begins. B: So it is. But why are there so many sandstorms recently? A: Because there is so much sand around us. B: Why is there so much sand? A: Because a lot of land has been _小题1:___ into sand. B: And why? A: Because people have __小题2:___ down a lot of trees. B: That may be the root(根源). We should __小题3:__ people from cutting down trees. Although we have built “ the Great Green Wall”, we still need to work hard to __小题4:___ the environment. A: I agree _小题5:__ you. Let’s go to the hill and plant trees on Sunday. B:Good idea. |