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。
