which是什么意思,which怎么读

don't change your mind, ______ happens to you. a. which b.
which country are you from? 3.i am from china.and you?
which season do you like best? i like spring best. why?
module 8 语法:定语从句 2 which and who. 学习目标
定语从句that和whichwho和whom