backwardi滞后backwardadj.向后的；落后的adv.向后backward- pumped反向抽运backward reference向后引用backward reasoning反向推理backward curvature[医] [脊柱]后弯, 脊柱前凸backward flashover反向闪络backward scattered反向散射的, 后向散射的backward extrusion反挤压,反向挤压backward stability后向稳定性backward vaned fan后曲叶片风扇backward slip zone后滑区