i picked up a man ___ i thought was honest.为什么不能填that

问题描述:

i picked up a man ___ i thought was honest.为什么不能填that
这里的关系代词为什么只能选who 而不选that

i picked up a man who (I thought) was honest
I thought 插入语,我觉得
我选了一个我觉得诚实/老实的人