Question

I'll show you a store [in which] you may buy all [that ]you need

A where ;which B in which ;that C which ;that D that ;that主句跟从句是什么关系，为什么选B

Answer 1

选B。 我是高中英语老师，这个题主要就是考察定语从句。第一空可填in which 或者where,它们都引导一个定语从句，in which 或者where在从句中做地点状语，指代in the store. 第二空只能填that，因为先行词是all,that也是引导定语从句，指代all(the things),在从句中做宾语。
主句是 I'll show you a store 第一个从句整个是[in which] you may buy all [that ]you need，修饰store
而其中[that ]you need又是第一个从句中的一个小从句，修饰all.