5. 挖出 

6. 不但 而且 

3. 对……有害 

4. 在正确位置 

1. 做调查 

2. 刷牙 

11. 再使用 

9. 形成 

10. 满不在乎地;粗心地 

7. 石油;原油;食用油 

8. 气体;煤气 

5. 土壤  6.煤 

3. 有害的   4.空的 

1. 调查   2.灰尘，尘土 

dig,  plant,  cut, blue, pollution, serious, wise, save,  environment,    realize

Andy. Do you know what we will do during our class trip      this weekend?

Wendy：We will climb the hill and have a picnic. And some      trees will be 1  at the foot of the hill.

Andy：Yes. We have already prepared some young trees. I      am so happy that I can do something to fight 2         . And

      I am looking forward to 3  in the ground         with my new spade (铁揪)  

Wendy： Yes. The dirty air is a 4 problem. With more        trees,we will have a 5   sky than before.

Andy: You,ve got the point. It's great that more and more

    people have 6  how terrible the problem is.       They are taking action to create a greener world.     Morepeople are taking part in 7  the Earth.

Wendy :That's good news. It is 8 of people to plant         trees.

    Trees are important in a clean and green 9  .

Andy:But we are not doing enough. I hope fewer trees in      the world are 10  down.

1.   2.   3.   4.   5.  

6.   7.   8.   9.   10.