I my homework at nine o’clock last Sunday morning.A. am doing B. was doing C. do

问题补充：

I my homework at nine o’clock last Sunday morning.

A. am doing B. was doing C. do

答案：

解析：本题考查时态。由句中的时间状语at nine o’clock last Sunday morning可以判断句中应用过去进行时。句意：上周日早上9点我正在做家庭作业。