We used to study in the old building ( ) was broken down last year括号中which 还是where请解释说明一下,

问题描述:

We used to study in the old building ( ) was broken down last year
括号中which 还是where请解释说明一下,

which

We used to study in the old building (which ) was broken down last year
the old building 是先行词,是定语从句which was broken down last year的主语

which
加这个which充当主语 引导此从句
where不能充当主语

which.....
做从句的主语。。。用which...
where...是做状语。。。