句型转换。

1. There is a bag on the chair. (改为否定句)

    There ______ a bag on the chair.

2. There are some bananas on the basket. (改为否定句)

    There ______ ______ bananas on the basket.

3. There are some cars in front of the tall building. (改为一般疑问句并作否定回答)

    ______ ______ ______ cars in front of the tall building?

    ______,  there aren't.

4. There are four students in the classroom. (对划线部分提问)

    ______ ______ students are there in the classroom?