backhoen.反向铲；反铲挖土机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 leaning rest仰卧撑back-channeling渠道返回BACK-ARC BASINS弧后盆地back-flap hinge明铰链back panel wiring板后布线back-scattering后向散射back e.m.f.反电动势back-mix-flowadj.逆混流的；反向混流的back-end design后端设计back search limit逆向限定搜索