根据要求进行句型转换（每空1分）
小题1:Tom was playing the piano when Mary bought a drink. (同义句转换)
While Tom _________ _________ the piano, Mary ___________ a drink.
小题2:Peter cut himself in the accident. (改为否定句)
Peter ______ ________ himself in the accident.
小题3:Why don’t you wait for us at the gate? (改为同义句)
________ __________ wait for us at the gate?
小题4:Emily was reading a book when the light went out. (对划线部分提问)
_______ _______ Emily _______ when the light went out?
