用恰当的介词 (in, on, of, at, with, beside或below) 填空。

1. Jim was surprised to see a foreigner go out             the lift.

2. "How many ways have you thought             to solve the problem?" the teacher asked.

3. Mary stood             the desk while her mother was explaining the problem to her.

4. Who sits              front of you in the classroom?

5. Do you often help your mother             the housework?

6. — When will the guests arrive here? 

    —             five minutes.

7. I live on the fifth floor. Linda lives two floors             me, on the third floor.

8. They planted some trees and flowers             every side ___________ the house.