题干

—How long _____each other before they _____here?
—For about a year.
A.have they known, comeB.did they know, came
C.do they know, comeD.had they known, came
上一题 下一题 0.65难度 单项选择 更新时间:2019-01-29 10:17:24

答案(点此获取答案解析)