I ____him since his childhood.A.have been knowing.B.had been knowing.为什么选B啊

I ____him since his childhood.A.have been knowing.B.had been knowing.为什么选B啊
I ____him since his childhood.A.have been knowing.B.had been knowing.为什么选B啊

I ____him since his childhood.A.have been knowing.B.had been knowing.为什么选B啊
我自从他的童年 A.have 的 ____him 是 knowing.B.had 正在知道

如果光看本句，确实觉得应该选A。 你看下是不是有上下文，整个语境是过去发生的事，这样选B就说得过去了

在过去的过去就知道了```````