dualadj.双重的；成双的n.双数dual flow双流dual tireadj.双轮的dual coat正反两用外衣,睛雨两用外衣dual bandn.双频；指手机可以在GSM900/1800频段之间自由切换；以保持通话不断dual node对偶结点Dual Echo双回波dual port双口Dual hard两硬dual unit两级制dual cone双纸盆,对偶锥