根据要求进行句型转换(每空1分) Tom was playing the piano when Mary bought a drink. (同义句转换) While Tom _________ _________ the piano, Mary ___________ a drink. Peter cut himself in the accident. (改为否定句) Peter ______ ________ himself in the accident. Why don’t you wait for us at the gate? (改为同义句) ________ __________ wait for us at the gate? Emily was reading a book when the light went out. (对划线部分提问) _______ _______ Emily _______ when the light went out?