secondum继发的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 compression次压缩second echo signal第二回波信号second development第二次显影second positioning二次定位second hand market二手市场second dehydration二次脱水second-rate work二流作品second anodization阳极氧化second runner-up第三名second order group二次群