3. _____________they go and work, they always help the local people.

2. They kept ____________the button, but nothing happened at all.

1. He ___________ just ___________when he heard a loud knock on the door.

10. We must put the waste things into d__________.

9. I am afraid you must p____ for the lost book.

8. Have you ever p_______ up apples?

7. Excuse me，have you got any books o_　 science?

6. My parents are very p______ of me.

5. I really hope my father can g_______ up smoking.

4. N______ of us has been to the Summer Palace.