问题补充:
—When did you come back?
—Half an hour ago. You to music.
A. have been listening
B. were listening
C. had listened
D. listened
答案:
A. have been listening
(答案→)B. were listening
C. had listened
D. listened
解析:考查时态。句意:—你什么时候回来的。—半小时之前,那时你们正在听音乐。根据句意是指在半小时前回来的时候,正在发生的事情,故使用过去进行时的时态。故B正确。