关于介词+which在定语从句中的用法，先看一个例子：This is the house which I was born in.=This is the house in which I was born.=This is the house that I was born in.=This is the house I was born in.=This is the house where I was born.可以看出，in which = where，in which中的in也可以放到句子最后。
就是说v+prep+地点时，可以用where，代替的就是prep+地点，如果用which，代替的就只是地点，所以在句中仍要用prep ，这样其实prep+which在定语从句中要确定这个prep用什么不是固定用法，而是要根据词组灵活搭配，前面举的例子中，因为是born in sw，所以用in which。你这句中的of which我想也是这样，因为有include of sth的用法，判断这个介词的时候，你就把这个介词拖到句末去看就是了。which 用于定语从句，作关系代词，在句中要做成分 in which 用于定语从句，作关系副词，在句中不做成分，in which=where in which 只能用在定语从句中，等于where,在定语从句中作状语。 如：He lived in the house in which Tom once lived. He lived in the house where Tom once lived. 定语从句中.如 this is the room in which we stayed 先行词是room，后的句子是用来修饰room的 但是room不可做stay的成分，因为stay是不及物动词，后不可直接家宾语 所以要有个介词． 其实上述的句子＝ this is the room which we stayed in． 这里的介词是可以提到which 前的 注意，第二个句子可用that 或省略 但第一个只能用which．只有which前可加介词其他介词的用法也类似于这种!
