用am, is, are 填空：
1. My eyes _______ big. My tail _______ short. I _______ a dog.
2. _______ you my mother? -Yes.
3. Who _______ she? - Jill.
4. Harry _______ my friend. I _______ his friend. We _______ friends.
5. _______ this the toilet? -No.
6. My father and my mother _________ tall.
