backwardi滞后backwardadj.向后的；落后的adv.向后backward flyaway直本后空翻下backward pulsing反向脉冲backward country经济落后国家backward voltage反向电压backward linkage向后连锁率backward pumping反向泵浦backward reading反向阅读,反读backward aspects落后面backward masking反向掩蔽backward stagger后向斜罩