such...that...和such...as的区别和用法

看例子：
This is such a difficult problem that all of us can't work it out.句中，that是从属连词，引导结果状语从句，在从句中不作成份。

This is such a difficult problem as all of us can't work out.句中，as 是关系代词，引导定语从句，在从句中作宾语。