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?