关于定语从句中as作引导词的用法! 老师讲过:主句中存在such、so、the same、as而且从句缺少宾语时,定语从句的引导词才能用as,比如: He is such a strange boy as people can’t understand 但是我又在书上看到了这样的句子: As is well known,China is developed fast.(作主语) The question is very simple,as indeed it is.(作表语) 是不是as作宾语时,才符合“主句中存在such、so、the same、as而且从句缺少宾语时,定语从句的引导词才能用as”这条规律?