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乌儿为什么会飞
更新时间: 2020-09-22 00:00:00  

鸟的身体外面是轻而温暖的羽毛,羽毛不仅具有保温作用,而且使鸟的外形呈流线型,在空气中运动时受到的阻力最小,有利于飞翔, 鸟类骨骼坚薄而轻,长骨内充有空气,头骨所有骨片完全愈合,胸椎和腰椎、荐椎和尾椎都相互愈。

鸟翅的羽毛构造,能巧妙地运用空气动力学原理,当它们作上下扇动或上下举压时,能推动空气,利用反作用原理向前飞行,羽毛构造合理,能有效的减少飞行时遇到的空气阻力,有的还能起到除震颤消噪音的作用。

关键词: 为什么

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