Contrapropeller
整流（螺旋）推进器, 整流螺旋桨, 同轴反转式螺旋桨
🗣️ 情景例句
Many business people turn off their pagers and cell phones during their leisure time.
许多商人在他们的休息时间里都把传呼机和移动电话关掉。
The (or A) beggar may sing before the thief (or footbad).
既是穷光蛋，何虑窃贼偷。
The man who had fixed up the air-line was also questioned.
安装供气管的那位工人也被提问。