题:i _(work)in the garden when he dropped in

问题描述:

题:i _(work)in the garden when he dropped in
请说明原因谢谢

I was working in the garden when he dropped in.当他来的时候,我正在花园里作业.when引导的从句,表示一个动作发生时,另一个动作正在发生,所以用过去进行时.