定语从句那些介词和宾语是连在一起的,比如look after look at,有没有不用介词前置连在一起的啊

定语从句中有时把和动词搭配的介词前置,放在关系代词前.形成”介词+关系代词（which、whom）“的结构.但是也不是所有介词都可以随意前置.当定语从句中的动词和介词是一个固定词组时,就不可以单独将介词前置.你说的look at/look after就是不可以将其中的介词提前的例子.例如：
This is the house which he was born in = This is the house in which he was born.
但是：This is the wounded soldier whom the nurse looked after in the war不可以变为下面的句子
This is the wounded soldier after whom the nurse looked after in the war.