Question

【题目】When I got to the classroom, my friend Bob＿＿the floor.

A. is cleaningB. was cleaningC. cleanedD. has cleaned

Answer 1

【答案】B

【解析】

句意：当我进教室时，我的朋友鲍勃正在打扫地板。

考查时间状语从句、时态。A. is cleaning（现在进行时）；B. was cleaning（过去进行时）；C. cleaned（一般过去式）；D. has cleaned（现在完成时）；when引导的时间状语从句指特定时间正在发生的动作，根据主从句时态一致的原则，判断主句用过去进行时，故选B。