what were you doing when he arrived为什么是 when 不是while when 和while 后面跟什么时态

what were you doing? what you were doing与what were you doing 差别what you were doing原句Do you remember what you were doing?是初二的知识, what were you doing 为什么是were不是what what were you doing _______(昨天晚上） what were you doing yesterday什么时态 what kind of work were you doing? Do you remember what were you doing 还是Do you remember what you were doing 急 what were you doing和whar you were doing的区别书上有what were you dong也有what you were doing,请问区别是什么 英语翻译Do you remember what you were doing do you remember what you were doing翻译 Do you remember what you were doing的翻译 what were you doing when he came to see you? what were you doing when you (hear) the news what were you doing this morning还是what are you doing this morning May I ask what you were doing in my restaurant yesterday?were doing 能不能换成did? What were you doing at this time yesterday?怎么回答 What were you doing at eight thirty last night?翻译 What were you doing at this time yesterday morning?