1、as we all know

例句：That, as we all know, is not only a possibility but a likelihood.

2、It is well known that

例句：It is well known that bamboo shoots are a panda's staple diet.

3、as everyone knows

例句：SIS, as everyone knows, gathers intelligence for britain overseas.

众所周知，秘密情报局为英国在海外收集情报。