Question

【题目】When the man downstairs knocked at the door, I_______.

A. am doing housework B. was doing housework

C. were doing housework D. am going to do housework

Answer 1

【答案】B

【解析】

句意:当楼下的人在敲门时，我正在做家务。当一个动作发生时，另一个动作正在发生，用进行时be doing，且根据knocked可知，用过去时，排除A和D，主语为I，用was，故选B。