用am, is, are填空。
1. Excuse me! ______ this your eraser? 
2. What ______ those? ______ they birds? 
3. This ______ his ruler. Where ______ my ruler?
4. I ______ in Class Three. ______ you in Class Three,too?
5. ______ these her English books?
6. Those ______ their apples. Where ______ his apples?
7. She ______ eleven. How old ______ that boy?
8. He ______ my friend. ______ your friend a boy or a girl?
9. ______ those maps? No,they ______ not. They ______ pictures.
10. These ______ your bananas. Here you ______.