初中英语知识点讲解：As在定语从句中的用法

as引导的非限制性定语从句位置较灵活，可以位于主句前面.中间或后面，一般用逗号与主句隔开，但which所引导的非限制性定语从句只能放在主句之后。例如：

(1) As is expected, the England team won the football match.

(2) The earth runs around the sun, as is known by everyone.