While John was playing the piano, Mary left the house.
John was playing the piano when Mary left the house.
While John was cleaning the room, Mary turned on the radio.
John was cleaning the room when Mary turned on the radio.
While John was shopping, Mary took the car to the car wash.
John was shopping when Mary took the car to the car wash.
在John……的时候（过程中：状态动词，可持续），Mary……(做动作：动作动词，终止性）
内容全部来源于网络收集，如有侵权，请联系网站删除：QQ：24596024