定语从句中“介词+关系代词“的结构如何使用？

“介词＋关系代词”，无非就是代替先行词的关系代词在从句中担任"介词宾语"。正确使用就要了解这个介词是根据什么来定的。
　　1。　介词是跟动词搭配，动词往往不及物，或动词短语带有介词。
　　　　I visited the city in which my father had worked for 10 years. (work in the city)
　　　This is a very important problem to which we all should pay attention. (pay attention to the problem)
这种情况一定要注意短语动词　look for, run into 之类的，整个视为一个单词，在句中不能拆开使用。

This is a problem most of us are likely to run into.
It is the right book that she was looking for.
2. 介词跟形容词搭配使用。
　　 Every student should do the assigned tasks for which they are responsible independently. (be responsible for)

3. 介词跟在名词后面
He had a wonderful chilhood, about which he wrote many stories. (stories about )
4. 状语是一个介词短语
　　 The professor wrote for him a letter of recommendation with which he applied for a position in that company.

　　　

　　　

定语从句中“介词+which”=where/when,在定语从句里作地点或时间状语，介词根据具体情况而变例如：
Do you still remember the time? We worked on the farm at that time合成定语从句
Do you stiill remember the time when (=at which) we worked on the farm?.
when/at which代替了at that time
Yesterday I visited the park. We planted many trees and flowers in the park last year
. 合成定语从句为
Yesterday I visited the park where/in which we planted many trees and flowers last year.
where/in which 代替了in the park
相信你能理解和赞同！祝你不断进步！