It when I my homework last night.
A. raining, did
B. rained, was doing
C. was raining, do
D. rains, was doing
网友回答
A. raining, did
(答案→)B. rained, was doing
C. was raining, do
D. rains, was doing
解析：句意：我天晚上当我正在做作业时，下雨了。结合语境可知主句描述的是过去发生的动作，用过去时态；从句强调的是过去某个时间正在进行的动作，用过去进行时态。故选B。