This is exactly what I need.
问题描述:
This is exactly what I need.
为什么不说 This is that I need.这是什么句式
答
定语从句,what代替了先行词和关系词,也就是This is the thing that I need
what=the thing that
其实that可以省略,它在从句中作宾语,也可以用which