定语从句中where什么时候都可换成介词加which吗？

在定语从句中
1、关系代词：who, whom, which, that, whose
指人：who, whom, whose, that
指物：which, that,whose
2、关系副词：when,where,why

注意：当从句的句子完整时，用关系副词;
当从句的句子不完整时，用关系代词。
（关系代词+介词in/on/at/of等=关系副词）

作主语，先行词是人用who/that
先行词是物用which/that
eg.一个男孩a boy
一个能讲三国语言的男孩the boy who/that can speak three foreign languages
一扇门a door
一扇木制的门the door which/taht is made of wood

作宾语，先行词是人用whom/that(who)
先行词是物用which/that
eg.一个女孩a girl
一个警察正在找的女孩the girl whom/that the police are looking for
一把钥匙a key
一把我昨天弄丢了的钥匙the key which/that I lost yesterday

whose 作定语，先行词可以使人，也可以是物,形式为whose + n.
一位学生a student
一位母亲生病的学生the student whose mother is ill
一个房子a house
一个窗子面朝南的房子the house whose windows face south

eg.I saw a tree. Its leaves were black.
→I saw a tree whose leaves were black.
=I saw a tree of which the leaves were black.
先行词指人：
whose + n. =the + n.+ of whom(或of whom + the + n.)
先行词指物：
whose + n. =the + n.+ of which（或of which.+ the + n.)

没有什么是绝对的，尤其是语言很灵活，我们所说的只是大多数情况，也有例外的

先行词，也就是where 从句所修饰的词是表示地点的名词时，可以换成介词加which

具体的还得看题

问你是哪一个的时候可以换。
如：where is my bag.换成which is your bag.的时候可以换