Question

【题目】John fell asleephe was listening to the music.
A.after
B.before
C.while
D.as soon as

Answer 1

【答案】C
【解析】：句意：当约翰听音乐时，他睡着了。A．after在……后；B．before在……以前；C．while当……时。强调主从句的两个动词同时发生。结合句意，故选C。