It has been almost five years _____ we saw each other last time.

It has been almost five years _____ we saw each other last time.
A、after
B、before
C、since
D、when
【正确答案】：C
【题目解析】：考查引导状语从句的从属连词的正确选择。句意为：“自从我们最后一次见面，至今已经近五年了。”since的意思是“自从……以来”，主句常常用完成时态，表示从过去某个时间开始持续到现在的动作。