backemfn.反电动势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backstyle high-jump背越式跳高backstepping approach反步法back-up of database备份数据库backlingual consonant舌根辅音back-up lamp switch后备灯开关Back of coat rides up背衩豁开back against the tide逆潮流back and forth method选择法backreflection camera背(反)射照相机back/forward sweep前推回代法