I my homework while my parents TV at 9 last night.A. did; have watchedB. had done; were

问题补充：

I my homework while my parents TV at 9 last night.

A. did; have watched

B. had done; were watching

C. was doing; were watching

D. would do; were watching

答案：

A. did; have watched

B. had done; were watching

(答案→)C. was doing; were watching

D. would do; were watching

解析：句意：昨天晚上九点钟当我父母看电视时，我在做作业。过去进行时表示过去某一时刻正在发生和进行的动作；故选C。