神马品牌网网站如何防止sql注入:as,which在非限制性定语从句中的区别?
来源：百度文库 编辑：神马品牌网 时间：2024/04/29 02:24:37
as,which在非限制性定语从句中的区别?
区别主要有两点
(1）as 引导的定语从句可置于句首，而which不可。
(2）as 代表前面的整个主句并在从句中作主语时，从句中的谓语必须是系动词；若为行为动词，则从句中的关系代词只能用which.。
which 在非限制性定语从句中，作为关系代词，可以做定语和表语。例如：
We told him to consult the doctor, which advice he took.(which在从句中做定语，修饰名词advice).
The two policemen were completely trusted, which in fact, they were.(which在此做表语）。
As 在非限制性定语从句中，可做关系代词。
例如：
The two brothers were satisfied with this decision,as was agreed beforehand.
(as 在此做关系代词，它的先行词是this decision
在从句中做主语）。