题干

We have been trying to train the young people who were hired last month,but they________their best to learn.
A.were not doingB.didn’t do
C.are not doingD.hadn’t done
上一题 下一题 0.65难度 单项选择 更新时间:2018-12-17 11:36:43

答案(点此获取答案解析)