除非你在空气动力学实验室工作，否则没有人知道汽车在空气的阻力下行驶时，75英里的时速比65英里要多消耗多少能量，事实是这个差距非常大。
Unless you work in an aerodynamic lab, you don't understand how much more energy it takes to push a car through the air at 75 MPH than at 65 MPH, but it's huge.
现代的飞机设计做得很好，但立足于燃料效率来看，飞机是否能设计得更符合空气动力学——降低阻力还是增加动力？
The modern airplane design works well, but from a fuel efficiency standpoint, could planes be designed more aerodynamically — to lower drag and increase lift?
的确鸟儿尾巴一样的飞机尾部改善了空气动力学性能，缓解了机体和机翼的阻力，同时还大大的增加了向上的力，缓释了由于飞机本身和货物重量而产生的向下的力。
But it was a birdlike tail that really amped up the aerodynamics, dampening the drag from the body and wings, as well as boosting the lift that lags under vehicle weight and cargo load.
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