时差N小时 马的腿为什么这么细?(上)（在线收听）

Why horses have skinny legs?

马的腿为什么这么细？

What's the use of a skinny leg?

这么细的腿有何作用？

The answer is Running.

答案是用于奔跑。

The skinniest lower legs belong to the fastest runners.

最细长的小腿能够赋予奔跑者最快的速度。

Think of how a deer can move, as opposed to a tortoise.

相比一只乌龟，想想一只鹿如何运动。

Why is that?

那是为什么?

It's because when you run, or indeed walk, you are constantly swinging the bottom halves of your legs.

这是因为当你在奔跑,甚至走路时,你的小腿部分要不断进行摆动。

For humans, one foot is stopped and essentially resting on the ground while the other is moving twice as fast as your overall speed.

对于人类来说,一只脚停止步伐时本质上是在地上,另一只脚则按照你整体速度的2倍进行运动。