按照要求进行句型转换。

1. The dictionary might be Li Lei's. (改为同义句)

    The dictionary might   _             _          Li Lei.

2. She had a cold because it was cold. (改为同义句)

    She had a cold ______ ______ the cold weather.

3 It must be Mary's. (改为否定句)  

   It  ______ ______ Mary.

4. Your brother has never heard of the story, _______ _______?  (完成反意疑问句)

5. This is Lucy's book. (对划线部分提问)

    _______ _______ is this?