as is known to all的语法

as is known to all的意思为众所周知的事。as在这里作关系代词，引导非限制性定语从句，指代主句内容。其引导从句既可以放句首的位置，也可以放句末。当as指代主句所讲述的内容时，也做关系代词。但值得注意的是，as在作关系代词时，极易被误认为是连接词而加用it。

例句：As is known to all，failure is the mother of success.众所周知，失败是成功之母。

as is known to all的近义词：as well known，释义：众所周知。此时as引导一个比较关系的状语从句，意为像......一样，为了加强比较的意味。