beforeness先前存在的条件
beforeconj.在 ... 以前pref.在 ... 以前;在..前面adv.以前;以往;之前
before and after study前后对比研究
before top dead center上止点前
before the term begins在新学期开始前
before-sale training售前培训
before the Qin Dynasty先秦
before the world war I第一次世界大战前夕
Before seeing a doctor就诊前
before everything else什么都暂且别提; 比什么都 ... 首先
Before Next Interaction下一次交互作用之前
before the Tang Dynasty唐前