单项选择题
Mary saw her son（）the piano when she came to the room.
A. playing B. play C. played D. to play
单项选择题 If you （） see Mr. Jim, you give him my regards.
单项选择题 Hardly （） a good job without putting his best foot forward at his job interview.
单项选择题 I prefer the climate in Kunming to （） in Wuhan.
