I'll show you a store in which you may buy all that you need.为什么用in which和that

I'll show you a store in which you may buy all that you need.为什么用in which和that
I'll show you a store in which you may buy all that you need.为什么用in which和that

I'll show you a store in which you may buy all that you need.为什么用in which和that
in which 即“在那里” ,that 后接从句,修饰all的.