backfinn.后脊(夹层；轧件舌尖；裂缝)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 step running后蹬跑back-step marks折标back up operation后备操作back suction wind反吸风back compensation后补偿backfilled ground填土地基back up behaviors后援行为back light source背光源back-dated bill将日期填早的票据back - colonism后殖民主义