用词的正确形式填空。

1. I have been                  (collect) stamps for five years.

2. You shouldn't                  (argue) with your classmates.

3. When he was very young, he took great more                  (interest) in science.

4. It was raining when the plane                  (land) in London.

5.                 (predict) the future can be difficult.

6. Could you please                   (not fight) with your classmates?

7. The girl was                   (shop) when she saw a car accident.

8. Miss Gao said                   (polite) "How do you do".

9. My father made a living by                   (sell) toys when he was young.

10. It's bad manner to ask                   (person) questions.