3. 樹木可以有助于保持水土。

2. 垃圾應(yīng)該被分為不同的類別。

四、完成句子

1. 那場大雨并沒有影響到比賽。

6. —Why didn't you answer my telephone yesterday?

  —Oh,sorry. I (wash) my hair.

5. (chat) with others on the Internet wastes too much time.

4. Air pollution makes people (feel) uncomfortable.

3. Don't you think it fun (skate) with your family in winter?

2. People should do what they can (stop) wasting.

三、動詞填空

1. Swimming skills (teach) in our school next term.

10. — What the accident,do you know?

   —I heard a little boy rushed onto the road suddenly.