Second law第二定律secondadj.第二的；次等的；再一个的num.第二n.片刻；秒adv.第二；其次v.支持；赞成；附和；调派second beating as assistance辅助式二次振捣second order mixed equations二阶混合型方程second leaf width and length第二片叶宽度及长度second-dose cholecystogram二次剂量胆囊造影(照)片second-harmonic generation二阶非线性光学效应second-hand clothing store旧衣店second-order scatter-ing二级散射（SOS）second generation instrument第二代仪器second stage of phagocytosis吞噬作用的第二阶段second to none in efficiency效率首屈一指