Simone
1.用as引导非限制性定语从句的：
Asweallknow；Aseveryone/ever来自ybodyknows；
Asisknowntousall360问答；Asisknownto战挥刻除everyone/everybody
2.用It做形式主语，that从句做真正主语的：
Itisknowntousallthat从句；
Itiskn改贵批百家似乙片owntoeve解让无感斯要ryone/eve备单每优rybodythat从句
3.用what引导主语从句的，后用that引导表语密序洲从句的：
Whatiskn宣队吗呼例课半章电owntousall阶范职齐鱼投社袁啊印序isthat从句；
Whatisknowntoeveryone/everybodyisthat从句
