用括号中所给词的适当形式补全句子。
1. I'm eleven, Mary is ten, so I am _____________ (old) than Mary.
2. Mary invites me _____________ (come) to her birthday party.
3. May I _____________ (help) you?
4. She is too young _____________ (go) to school.
5. Here is the key to your suitcase, you can _____________ (lock) it.
6. How many _____________ (bus) are there in the picture?
7. Ten hundred _____________ (be) a thousand.
8. She likes _____________ (go) on trips.
9. Look, she _____________ (fly) a kite.
10. It's time _____________ (listen) to the teacher.