她在学生中间很受欢迎,这是普遍知道的。
但是,as,which引导定语从句时还是有区别的:
1.当从句位于主句前面时,只能用 as。如:
As is known to everybody,the moon travels round the earth once every month.
月球每月绕地球转一周,这是每个人都清楚的。
As is often the case,the girl forgot to take her dictionary.(不能用which)
经常是这样子的,那个女孩忘了带字典。
2.as 引导的非限制性定语从句应与主句在意义上和谐一致,which无此限制。如:
He went abroad,as (which)was expected.他出国了,这是大家预料到的。
He went abroad,which was unexpected.他出国了,这让大家感到很意外。(不用as)
3.as 引导非限制性定语从句时,先行词通常不能是主句中某个具体的词,而应是整个句子、整个短语或某个短语推断出来的概念,而which 则无此限制: