1. —You shouldn't shake hands with her. You should bow.
    —I'm sorry. I don't know the _____  here.
2. There are lots of _____  in the school. You must obey them.
3. There are many trees on both _____   of the street.
4. The machine doesn't work. Is there_____   wrong with it?
5. He_____  the present yesterday, but he didn't want to accept it.
6. The policemen_____   the thief by the arm.
7. When we were in Shanghai, we took many photos with a _____  .
8. It often rains in England. When you go there you'd better take an _____  .
9. The actor's _____  is very wonderful. We are interested in it.
10. You can buy this medicine in a _____  .