backemfn.反电动势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-up water level回升水位back-to-back test成对试验,整流子片试验Back-door criterion后门准则back trace of history历史回溯back pressure circuit背压电路back perspective view背面透视图back-stair intrigue[法] 密谋backscatter radiation(分)散(放)射backscattering sensor后向散射仪Back - to - front从后排至前排

back and fillvi.看风使舵前进以避开障碍(反复无常)