firsthandadj.直接得来的；第一手的adv.直接地firstadj.第一的；最初的adv.首先；第一n.最初；(序数词)第一first-order constraint qualification一阶约束品性First derivative stripping voltammetry一阶导数溶出伏安法first-simple support back continuous先简支后连续First American Title Insurance Company第一美国产权保险公司first-order differential reflectance一阶微分反射比first order linear difference equation按揭贷款first-aid medical information system急救医学信息系统first-order-in-frequency analysis主频率分析first-order asymmetric transformation[化] 一级不对称转换first-inquiring responsibility system首问责任制