backguyn.拉索；拉条；支撑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 oscillator后备振荡器back-seat driver不断地告诉司机如何开车的乘客back-berm trough滩肩后凹槽backwash procedure反洗程序backtracking point回溯点backword reasoning反向推理backplate assembly后挡盖组件back ampere-turn逆向安匝数,反作用安匝back lighting bulb暗闪灯backwashing method回哩