I______ housework when there was a knock at the door.

admin2009-08-17  32

问题 I______ housework when there was a knock at the door.

选项 A、did
B、was doing
C、am doing

答案B

解析 本题考查动词时态。when引导的时间状语从句是一般过去时,主句也应用过去时,又因为主句动词do是延续性动词,所以主句时态应用过去进行时。
转载请注明原文地址:https://kaotiyun.com/show/98vd777K
0

随机试题
最新回复(0)