1. 根据句意,选用方框内的词组填空。注意形式的变化。

add up, take part in, take action, make a difference, cut down, be good for, hear of, be harmful to, pay for, begin with

1. （1） The students air pollution by walking to school last term.
3. （2） Your help has . I understand the work better now.
   
5. （3） All the people in the kingdom the magic cloth before the king saw it.
   
7. （4） Pollution our health. So we must protect our environment.
9. （5） "The food you though it tastes awful," my mother said to me.
11. （6） Last Friday we had a sports meeting. I the basketball match.
    
13. （7） They said they to protect the environment already.
15. （8） It seems unfair for him to make him everything.
17. （9） Five and eleven to sixteen. Is it right?
19. （10） First of all, I an apology for a mistake I made last week.