We first met on a train in 2000.
We both felt immediately that we ______ each other for years.
A. knew B. have known C. had known D. know
We first met on a train in 2000.
We both felt immediately that we ______ each other for years.
A. knew B. have known C. had known D. know
C 考查时态：第一关键信息为first met in 2000，接下来for years 提示know 动作在felt之前，即过去的过去，因此答案为过去完成时had known。