定语从句 关于介词提前麻烦哪位大师帮我把定语从句中介词提前的部分讲一下,最好细一点.（可以结合下面的例句）October

介词 + 关系代词”引导的定语从句
介词加关系代词引导的定语从句要注意以下几点：
1．“介词 + 关系代词”引导的定语从句时,介词的宾语只能用which（指物）和whom（指人）,即：介词+which/whom.不能用that 和who.
　e.g. This is the teacher from whom we’ve learned a lot. 这就是从他那里我们学了很多东西的老师.
　　Great changes have taken place in the city in which we live. 　我们所居住的城市发生了巨大的变化.
2．有时介词也可放在从句的末尾,这时关系代词可用which/that(指物),who/whom/that（指人）,也可以省略.
e.g. The situation (which/that ) we had got into was very dangerous. 我们当时的处境很危险.
　The man (whom/who/that) you were talking to just now is my English teacher. 你刚刚和他谈话的那个人是我的英语老师.
3．当定语从句中的谓语动词短语是固定搭配,不可分割时,那么动词短语中的介词不能前置.
　　e.g. This is the pen which I’m looking for. 这是我正在找的那支钢笔.
　　　　不能写成：This is the pen for which I’m looking.
4．定语从句也可由“名词/代词/数词+介词+which/whom”引出.
　e.g. That old man has two sons, one of whom is a doctor. 那个老人有两个儿子,其中一个是医生.
　The house, the windows of which ( = whose windows = of which the windows) were damaged, has now been repaired. 窗子遭破坏的那栋房子现在已经修好了.
5．引导定语从句的关系副词(when, where, why) 可以用“介词+关系代词”代替.
　　e.g. I’ll never forget the day when I joined the party. (when= on which). 我永远都不会忘记入党的日子.
　　　The factory where my father works is in the east of the city. (where = in which). 父亲工作的那家工厂在城东.
　　None of us know the reason why Tom was absent from the meeting. (why = for which). 我们都不知道汤姆缺席会议的原因.
6．“复合介词短语+which”引导的定语从句,常与先行词用逗号隔开,而且定语从句常用倒装语序.
　　e.g. He lived in a big house, in front of which stood a big tall tree. 他住在一幢大房子里,房前有一棵大树.

定语从句中介词提前的部分讲一下
那不是什么介词提前的部分，而是前面那个词的意思等于括号中那个词组。
When根据意思可以替换成On Which（在某一天）In Which（在某一段时间里）At whcih（在某个时刻）
Where根据意思可以替换成On Which（在......上面）In Which（在.....里）At whcih（在......小地方 ）
wh...