用所给词的适当形式填空。
1. Oh, it's seven o'clock. It's time______ (go) to school.
2. The box is too heavy. Let me ______ (help) you.
3. Lily _____ (have) some picture books.
4. Listen! Who ______ (sing) in the room?
5. There ______ (be) a boy and some girls over there.
6. Sometimes he _______ (watch) TV in the evening.
7. The two boys are _______ (China).
8. Tom, with his friends, _________ (be) playing football over there.
9. There are five ______ (sheep) under the tree.
10. There are many _____ (cloud) in the sky.
