用am, is, are, have, has, there is 和 there are 的适当形式填空。
1.________a book on the desk?
2.Our classroom ________ clean, but their classrooms ________ dirty.
3.My father ________ a doctor. He ________ a new car.
4.—________ I your English teacher?
—Yes, you ________.
5.________some boys on the playground.