Backal口腔锭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-tackle转身向后抢断球back moulding底饰back flushing反冲backless shoe无跟鞋back abutment台背back contract远期合同back lighting背面补光,逆光照明,背景光,背光照明,后照明,背面照明back mutation复原突变,反突变,回复突变back impeller[化] 后弯叶轮; 后弯式叶轮backing space前级空间