成人英语三级

--How long____each other before they____married?

--For about a year.

A. have they known; get

B. did they know; were going to get

C. do they know; are going to get

D. had they known; got

D got married是主系表的过去时，got在此时是系动词，married是形容词。  过去的过去 how long 过去 got married

从上图可以看出，how long指的是从过去的过去一直延续到got married，所以应该用过去完成时。