过去进行时主要有以下用法： 1、谈论过去的某个时刻或某段时间正在进行的事。例如：I was reading the newspaper at 6.30 this morning. 2、当过去某一件事情发生时，另外一个动作正在进行。此时，延续性动词用过去进行时，瞬间动词用一般过去时。例如：The earthquake started while I was doing some shopping. 3、可以表示从过去某个时候看来将要发生的事。例如：When his son arrived, the old man was dying.
1.I came to your home yesterday afternoon, but nobody was in.
Oh, we_______ some shopping in the supermarket.（2007年南通）
A. have done B. did C. were doing D. are doing
2.What do you think of the colour of my new dress?
Sorry, but what did you say? I_________ about something else. （2007年扬州）
A. think B. thought C. am thinking D. was thinking
3. I _______my homework while my parents TV last night.（2006年南京）
A. did; have watched B. was doing; were watching
C. had done; were watching D. would do; were watching