The town ( which / that ) we visited last month is the one( where / in which ) the famous painter was born.
定语从句中引导词的选择关键是看先行词在定语从句中的功能,也就是该词在定语从句中作什么成份.
we visited the town.
因此,要用关系代词which 或that来引导定语从句；
the one=the town
the famous painter was born in the town.
因此,要用关系副词where 或介词in后接关系代词which来引导定语从句；