有关in which的用法?

我知若用定语从句时,若子句最后有介词,则要将其介词调前例: I live in Hong Kong. Hong Kong is a prosperous metropolis.Hong Kong is a prosperous metropolis in which I live.但想问以下句子为何会用in which?1) The recent incident in which four women were driven to death or the verge of death from septic shock after accepting a treatment at a beauty centre is a case in point.2) An automobile accident in which driver fails to stop and identify himself or herself.3) He has four months in which to lodge an appeal.第一题在which前删去in,变成The recent incident which four women were driven to death or the verge of death from septic shock after accepting a treatment at a beauty centre is a case in point.可不可以? 2015-03-11 07:13:24 补充 In which......是用于形容箾面的事物，即是recent incident但where是用于描述地方即when用来描述时间一样而incident不是地方，为何会用where(in which)？ 2015-03-11 07:24:34 补充 1) 我知This is the school which we met each other.(不正确)但为何I've finished the book which I borrowed from the library.(正确)是不是因为book不是一个地方?没有(在...其中)的意思但incident也不是一个地方2) 第3条 : He has four months in which to lodge an appeal.four months 是一个时间劬可以用where=in which?

on which in which的用法 总是弄不懂 比如Science lays the foundation ...答：这样吧，这位网友，关于关系代词前面的介词是 on 还是 in 还是别的什么，用一个办法来试一下： 既然关系代词which是指前面的先行词（被定语从句“定”的那个词），因此可以把那个先行词像代数一样暂时代过来，把关系代词换下来，比如你给的这个例...

这个问题我还想问问老师呢