1 . Some people don’t know too much fruit juices can be ________ to children’s teeth.

A．close

B．polite

C．normal

D．harmful

2 .
1. The students____________air pollution by walking to school last term.
2. Your help has_____________. I understand the work better now.
3. All the people in the kingdom_____________the magic cloth before the   king saw it.
4. Pollution____________our health. So we must protect our environment.
5. "The food ________you though it tastes awful," my mother said to me.
6. Last Friday we had a sports meeting. I__________the basketball match.
7. They said they_____________to protect the environment already.
8. It seems unfair to make him______________everything.
9. Five and eleven______________to sixteen. Is it right?
10. First of all, I____________an apology for a mistake I made last week.

3 .
1. Everyone in this town should________ ________ _________(参加) cleaning the city up.
2. Do you want your address written________ ________ _________ ___________(在......顶端) the letter?
3. So together, our actions can_______ _______ ________（发挥作用）．
4. His eyes were open and everything he saw was______ ______(颠倒).
5. Smoking________ ________ _________(对......有害) your health. You must give it up.