backward pig发育不良的仔猪backwardadj.向后的；落后的adv.向后backward-facing step flow后向台阶流backward-action regulator[电] 逆向作用调整器backward scattered electron反向散射电子, 后向散射电子backward Monte Carlo method逆向蒙特卡罗法backward inclined fan blade后弯式风机叶片backward-wave oscillation返波振荡backward version management向后版本管理backward chaining procedure逆向链接过程Backward Chaining Reasoning反向链推理Backward Linkage Spillovers后向链接溢出