I know nothing about him except that he is from the south

题目

I know nothing about him except that he is from the south
为什么一定要用that啊·?

答案

因为that he is from the south这个从句是宾语 nothing 的平行结构
你看：
I know that he is from the south
he is from the south的意思已经很完整,故选无意义的that 了
全句意为：
我只知道他是南方人