请问怎麼填：Is this school ___we visited 3years ago? Is this the school ___we visited 3years ago?

is this school the one (which)we visited 3 years ago?
这是三年前我们拜访的那所学校吗顺便帮忙解释下~~填that 或which看前面有没有 the，is this school which we visited 3 years ago?is this theshool that we visited 3 years ago?