We first met on a train in 2000We both felt immediately that we each other for years.A.

问题补充：

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

答案：

A. knew

B. have known

(答案→)C. had known

D. know

解析：考查时态。句意：在2000年我们第一次在火车上相见，我们都立刻感觉到我们多年前已经认识了。根据句中时态用一般过去时，可知用过去的过去，即过去完成时，选C。