It is ten years _____ I last saw her. A. after B. since C. for D. that

问题描述:

It is ten years _____ I last saw her. A. after B. since C. for D. that
为什么不能选A

B.固定搭配it is/has been+time since+.自从我上次见到他已经(至今)10年了.after是指在一个动作之后的一个动作或状态,不能持续至今.