second DO第二个循环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Secondarg dysmenorrheal继发闭经second-hand equipment二手设备second fundamental form第二基本形式second-site mutations第二位置突变second language learner第二语言学习者second level bootloader二级引导程序Secondcary salinization次生盐渍化second mortagage crisis次贷危机second order subroutine二级子程序secondorder sensitivity二次灵敏度