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：本句的意思是“当地震发生的时候，我正打扫卫生。”，根据意思可知，本句应该用过去时，故排除AD；start是一个非延续动词，所以不能用进行时表示“正在开始”，故排除C。所以本题选B。