问题描述: What were you doing when the UFO arrived?是个什么时态的什么句子?有主从句的事态要求么? 1个回答 分类:英语 2014-10-07 问题解答: 我来补答 What were you doing when the UFO arrived?主句是过去进行时”你当时在做什么?”从句是过去时”当UFO到达的时候”当UFO到达的时候你正在做什么?就是这个意思给你个例子:what are you eating when your mother left home?意思是:当你妈妈离开家的时候你正在吃什么?和你说的句子基本一致 展开全文阅读