小笨猪seven
beforebefore[英][biˈfɔ:] [美][bɪˈfɔr,-ˈfor] prep.在……之前;先于,优于;当着……的面;与其……conj.在……之前;在……以前;比……早些;与其……adv.先前,从前;在前,在前方
钮咕噜嘟嘟
时间上:before 可用在时间状语从句中,例如:He has left the room before I came in.位置上:in front of 在……前面,是指两个独立的物体,例如:The post office is in front of the shop. in the front of在……的前部,是指一个东西在另外一个东西的前部,例如:He sits in the front of the classroom.祝你学习愉快!