1.
two or four athletes respectively,
双人双桨，四人双桨，
2.
Duplex (pressure)gauge
双工[双针]压力表
3.
double-head arrow
双箭头(双头指针)
4.
double quotation marks ((""))
双引号((""))
5.
douBle deliciousness, douBle pleasantness
双重美味，双重愉悦
6.
binocular microscope
双目显微镜,双筒显微镜
7.
dual two trailing shoe brake
双向双从蹄式制动器
8.
double-action pump
双动泵，双作用(活塞)泵
9.
bidirectional flow
双向流动, 双向流(程)
10.
dual two leading shoe brake
双向双领蹄式制动器
11.
double bleaching with sodium chlorite and hydrogen peroxide
亚氯酸钠双氧水双漂法
12.
double-action disc harrow
(双列圆盘靶) 双功圆盘靶
13.
dizygotic twins
二卵双生，异卵双生
14.
double-sided plush
双面绒,双面长毛绒
15.
bifilar helix biperiodic electrostatic focusing
双螺线双周期静电聚焦
16.
twin wheel twin nozzle type turbine
双轮双喷嘴式水轮机
17.
A binocular or field glass.
双目镜，双筒望远镜
18.
two person two eye surgical microscope
双人双目手术显微镜