He asked me—— I was busy with those days

问题描述:

He asked me—— I was busy with those days
A.that B.what C.if D.why
这题应该选什么?什么时候可以用that,什么时候可以用what?

用what,这里从句里面缺宾语,用其他的句子不完整.
在宾语从句中
what 有指代意义,即可直接代替一个名词出现在句中
that 可认作一个虚词,无指代意义,也就是说需要有一个先行名词.