Backen.巴克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 label书标backshield散射线遮挡, 散射线屏蔽back catch门后钩backmixingn.回混Back Color背景色back break超爆,超欠挖back lever后水平backtender造纸工段看管工,后整理工back gauge车轮内距,反向行程限位器,背缘尺,边距,后支档back track由原路退回