根据首字母提示填单词

1. Probably your boy threw it away, thinking it was w    _     paper.

2. This had a great e     __  on the future of both mother and son.

3. The police formed a h       _  wall around the building.

4. The new law will reduce p           of the air.

5. There was less o         at t.he top of mountain.

6. Most of c          was carried out of Shanxi Province in China.

7. Some plants is probably p    _     ,but they can be made into meclicine.

8. N    _     children are much healthier.