ONWHICH的用法？

inwhich:在......里面；onwhich:在......的上面，或具体时间的某一天onwhich和inwhich都可以用来引导定语从句，修饰先行词，区别在于介词on/in这取决于先行词的搭配比如:Ican'tforgetthedayonwhichwehadaparty.这个句子，先行词是day，原本的搭配是ontheday.Iliketheroominwhichtherearemanytoys.这句话的先行词是room，词组搭配是intheroom。