1、应明确非限定性定语从句恐怕只有as和which可代整个主句,而这两个词能用介词+关系代词替换吗?我还找不到这样的例子。
This is a house,in which we once lived.
which代指house,而不是整个主句。
如果是说介词+关系代词可否引导非限定性定语从句,答案是肯定的,而且“介词+关系代词”前可有some, any, none, both, all, neither, most, each, few等代词或者数词
He loved his parents deeply, both of whom are very kind to him.
2、可以。zlw3565584说的对。
3、as引导的定语从句能代替前面的单个词,as是个难点。as引导限制性定语从句主要结构有:the same…as as…as such…as so…as (是不是觉得很熟?) 主句中出现the same, as, such, so修饰先行词,需选择as做关系代词在定语从句中做主语或宾语。
It’s the same person as we wanted to find yesterday .
我们昨天要找的是同一个人。
as引导定语从句更多参考见
http://teacher.cersp.com/classroom/yingyujiaoan/200703/927.htmlhttp://zhidao.baidu.com/question/7545241.html