This is such a difficult problem as can't be solved by us.
情判断这个句子是否有误。如有误如何改正。
改正:This is such a difficult problem that it can't be solved by us.
我觉得句子没有错误。
根据传统语法:as 为关系代词,指代先行词 problem,在从句用作主语。
根据现代语法:as 为连词,引导比较分句,由于比较分句的主语为主句比较项 a difficult problem的对应项,习惯上要省略,所以as后面的分句空缺主语。
我觉得这个句子是正确的。as是关系代词引导定语从句,并且在从句中作主语。