He told us all ( ) he knew about computers.为什么填that和what都行

问题描述:

He told us all ( ) he knew about computers.为什么填that和what都行

all that =====what

句子的意思:他把自己所有的电脑知识告诉了我们.
不管that还是what都可以指代宾语从句he knew about computers.