-What was wrong with you yesterday evening?-I my homework when the light went off

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。