Prexa普雷克萨牌手表PREabbr.Petroleum Refining Engineer炼油工程师prequasi - invex预不变拟凸函数prerecorded signal预记信号pre-chlorination预氯化pretrail detention审前羁押prefocus lamp base预调焦灯座premaxillary gland前颌腺preloaded concrete预压混凝土preflame oxidation预燃氧化precast ele-ment预制构件preformed antibody预成抗体