How do houseflies land on the ceiling?
[ 2006-07-26 09:54 ]
蒼蠅幾乎可以停在任何地方，豎直的玻璃，天花板……我們認(rèn)為這是理所當(dāng)然。可是，為什么蒼蠅能毫不費(fèi)力地倒站在天花板上呢？想知道答案？那就趕緊來(lái)看下面這篇文章吧。
 Flies nearly can land on every place. When they land on the
ceiling, they're upside down. We take it for granted, but think about this
one...When the fly is heading for the ceiling, it's flying right side up. When
it lands on the ceiling it is upside down. At some point along the way it has to
flip over. But when? And Where? And How?
Scientists dispelled the
prevalent theory, that the fly performed a fighter pilot-like barrel roll just
prior to landing, by capturing this momentous event on film.
Freeze
frames, from the high-speed cameras scientists used, proved that flies don't
flip, but flop, as they land upon the ceiling. Prior to impact, the fly extends
its forward legs over its head, makes contact, and uses the momentum it has
gathered in flight to hoist the
remainder of its body to the ceiling. Thus, the fly proves to be more of an
acrobat, than of a fighter pilot
practicing his maneuvers.
Once the fly reunites all six
feet on the ceiling, it keeps things dazzlingly exciting, by gracefully
tiptoeing across the ceiling,
securing itself by using sticky pads found under the two claws attached to each
of its feet. It is because of these sticky pads and the hairs on the legs that
the fly is such a carrier of disease germs.
Did you know? The entire life
of a housefly is spent within a few hundred feet of the area where it was
born.
hoist 提升，升起
acrobat 雜技演員
maneuvers 技術(shù)
tiptoe 用腳尖走
（英語(yǔ)點(diǎn)津 Annabel 編輯）
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