where一般等于“介詞+ which”,
你把定語從句從句部分還原成正常的句子,看是否需要加介詞,如果需要加介詞,那么用where或介詞+which（這里不能用that）都可以,如果不需要加介詞,就直接用which 或that,不能用where,例如：
this is the house in which/where i lived last year,這個句子中還原為i lived the house是不行的,缺了一個in,應(yīng)該為i lived in the house,因此要用in which,在這里就等于where
this is the place which/that i visited last year.這個句子中還原 i visited the place 是行得通的,不需要加介詞,因此直接which/that ,不能用where