A:hello!haven't seen you for a long time!how are you?B:fine.what about you?how is everything going?A:Not bad.where do you stay now?B:I am studying in the Middle school.A:oh.sounds great.so do you live...大哥。。。department是n.部门, 系, 科, 处, 局 n.知识范围 的意思-.-department 还有公寓的意思