问题补充:
-How long each other before they married?
--For about a year.
A. have they known; get
B. have they known; were going to get
C. do they know; are going to get
D. had they known; got
答案:
A. have they known; get
B. have they known; were going to get
C. do they know; are going to get
(答案→)D. had they known; got
解析:谈论的是过去的事情,从句用一般过去时,主句动作发生在从句动作之前,用过去完成时。