问题补充:
---- What was wrong with you yesterday evening?
---- I my homework when the light went off suddenly.
A. doing
B. was doing
C. did
D. have done
答案:
A. doing
(答案→)B. was doing
C. did
D. have done
解析:考查情景交际。“昨晚你怎么了?”“我正在做作业时,突然断电了。”过去某时刻正在发生的事情用过去进行时。故选B。