It is the place( )we work in. This is the place ( )we work. This is the place ( )we visit.This is the place ( )we work in.Is this the place ( )we work?Is this the place ( )we work in?要答案和讲解

It is the place( )we work in. This is the place ( )we work. This is the place ( )we visit.This is the place ( )we work in.Is this the place ( )we work?Is this the place ( )we work in?要答案和讲解
It is the place( )we work in. This is the place ( )we work. This is the place ( )we visit.
This is the place ( )we work in.
Is this the place ( )we work?
Is this the place ( )we work in?
要答案和讲解

It is the place( )we work in. This is the place ( )we work. This is the place ( )we visit.This is the place ( )we work in.Is this the place ( )we work?Is this the place ( )we work in?要答案和讲解
都是定语从句的范畴
This is the place (which,)we work in=This is the place in which we work
因为有了in,从句中缺宾语,因为work是不及物动词
Is this the place ( where )we work
没有介词in ,从句不缺宾语,缺状语,用关系副词,where=in which
This is the place (which )we visit
visit及物动词,从句缺宾语,用关系代词

which 从句中缺个in 介词的宾语，所以which
where 从句中缺个地点状语，所以where
which 从句中缺个宾语，所以which
主要看从句中缺什么成分

第一空：which，in which 这个介宾宾语前置引导这个定语从句。
第二空：where = in which，但这里定语从句需要一个关系副词，所以where最恰当。
第三空：that/which/where 都可以。