Fill in the correct form of the verb to be (am, is, are).
1. I am fine, thank you.
2. Who is that boy?
3. Where are my shoes?
4. It is a nice cat.
5. My exercise books are in the schoolbag.
6. This is John.
7. Bob is not here today.
8. Carol, is this your bike?
9. We are in the classroom.
10. How are you today?
11. Where is my brother?
12. How old are you?
13. I think you are tired.
14. I think his pen is black.
15. It is green.