double box双窝doubleadj.双重的；成双的；两倍的v.翻一番；使 ... 加倍n.两倍；双份double the amount使数额加一倍double jet stream双急流double mass curve双累积曲线double angle iron槽钢double gum lancet双头牙龈刀double arm pusher双杆推钢机double size ripple双值纹波double-pole fuse双极熔断器double tube method双管法double-line pile双排桩