题干

—Can you tell me if Tom has finished his homework?
—I've no idea. He ________ it this morning.
A.has being doingB.had done
C.is doingD.was doing
上一题 下一题 0.64难度 单项选择 更新时间:2014-04-19 05:08:05

答案(点此获取答案解析)