明月openwrt教程:非限制性定语从句怎么用?

非限制性定语从句
1.非限制性定语从句由 who, whom, which 引导（不可用 that），还可以由 whose, when, where 等词引导。

非限制性定语从句要用逗号隔开，非限制性定语从句可以删去，整个句子的意思还是完整的，而限制性定语从句如果被删去，句子的意思不完整。

例如：

Mr Brown, who is our English teacher, lives near our school.

Yesterday I met my son’s school master, whom you saw at my home last year.

He has finished the difficult exercise, which is easy for you.

The factory is headed by a 35-year-old man, whose wife is from America.

They will fly to Qingdao, where they plan to stay for two weeks.

In these days, when I was a child, the city had no industry to speak of.

注意：非限制性定语从句中的关系词是不可省略的。

2.非限制性定语从句有时并非修饰名词或代词，它可以修饰整个句子。

例如：

They have invited me to visit their country, which is very kind of them.

3.in front of, at the back of, in the middle of 等短语在定语从句中的用法。

如果关系代词是作这类介词短语的宾语时，介词短语必须提前。

例如：

Yesterday afternoon we arrived at his log cabin, in front of which stood a tall

tree.

4.注意此类句子表达方式。

There are forty students in their class, thirty of whom are League members.

也可以改成

There are forty students in their class, of whom thirty are League members.