little has been done that is helpful to our work其中的 that能换成all that 么?为什么?

问题描述:

little has been done that is helpful to our work其中的 that能换成all that 么?为什么?

不能,因为all完全是突然冒出来的,多余的。

不能 that 是 little 代词的 定语从句的先行词 不能换成all that