backmen后卫backn.后面；背脊；靠背；后背；后卫vt.支持；后退adv.向后地adj.向后的；后面的；偏远的；过时的；积欠的back-end data base system[计] 后端数据库系统Back down from doing sth.放弃做某事。back-up reference station后备参考站backstage management system后台管理系统Back sleeve for rocking arm摇臂后套back into sync with reality重新回到现实中back firing detective relay逆弧检测继电器Back to back duplex bearing成对双联轴承back-to-back connection背对背连接,交叉连接backscattering spectrometry后散射能谱测定法