用所给词的适当形式天空。

1. John has two ______ (knife) .

2. The pen isn't mine. It's ______ (she).

3. What color are ______ (this) coats?

4. My friend and I ______ (be) students.

5. What ______ (do) he look like?

手阳明大肠经的经穴可治疗牙痛，尤其以治疗下齿痛为主。