定语从句中 on which ,at which,in which 怎么 用

on which。the day对应which。I join the league 在具体的某一天用on。后半句展开来就是 I join the league on the day.which 作the day的定语。on the day变成on which.

还不明白可以百度HI

用on which ，因为固定搭配 on the day
which前的介词，要看从句中的动词或者看先行词的饿搭配
先行词的搭配就是你的例题
the school he goes is best,这句是根据从句中的动词go选的，固定搭配go to school,，
所有的介词+which都是这两种情况，用时就是得记住固定搭配

你说的on which,at which,in which是关系副词，都是由介词+关系副词“which”组成的。
给你几个同样的列子：why=for which
where=in/at/on... which
when=during/on/in... which

注意：that前不能加介词。