5. 在绿色学校，每个班级都收集可回收或再次使用的废品。 

At a green school,every class        waste      can be        or        again.

4. 他们使用了太多的油，也导致了污染。 

They use        oil and cause pollution         .

3. 在一些地方，来自工厂的污染蔓延到了城市和村庄。 

In some places,pollution        factories        cities and villages.

2. 谈论我们不能做的事情是没有用的。 

It's no use     things we can't do.

1. 在(学完) 关于环境的课程后，我在担心我们的将来。

After our lesson        the        ，I'm      the future.

(  ) 2.        everyone starts to do something,the world will become more and more beautiful.

   A. Unless   B. If

   C. Though   D. While

5. Some waste or rubbish can be        (回收利用) .

4. Now the situation is        (无望的) .

3. Most students have 1         sleep before their exam.

2. Pollution is our great e         . We should fight against it.