问题补充：
---Were you at home at 7:00 yesterday evening? I called you but no one was there.
---Sorry, we a movie at the theatre at that time.
A. watch
B. were watching
C. watched
D. are watching
答案：
A. watch
(答案→)B. were watching
C. watched
D. are watching
解析：句意：--昨天晚上七点钟时你在家了吗？我给你打电话但是没有人接。--抱歉，在那时我们正在剧院看电影。联系句意得知是在过去的某个时间中正在进行的动作，要用过去进行时，故选B
