The earthquake when I some cleaning.
A. starts, was doing
B. started, was doing
C. was starting, was doing
D. starts, were doing
网友回答
A. starts, was doing
(答案→)B. started, was doing
C. was starting, was doing
D. starts, were doing
解析：根据语境可知此句的含义地震的时候我正在打扫卫生。此题重点考查的是when引导的状语从句表示当…的时候。其强调的是当一个动作发生的时候另一个动作正在进行，强调状态，故选B。