问题
选择题
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
答案：C
题目分析：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。