Dualleh杜阿莱dualadj.双重的；成双的n.双数dual-rate spring可变刚性弹簧dual address stack双地址栈dual channel audio双通道音频dual - co-sine双余弦dual magnification双重倍数Dual Steiner point对偶Steiner点dual contradiction矛盾二重性dual period effect双周期效应dual robots system双机器人系统dual purpose trust[经] 双重目的信托