托福听力课外资料练习：科学美国人60秒小朋友走路更容易累的原因相关内容分享

2017年07月17日17:22 来源：小站整理: 参与（0）阅读（3447）

摘要：托福听力的备考十分的重要，那么你应该如何练习呢?在备考过程中除了一些真题之外，一些常用的课外资料也是十分重要的。小编经常用到的就是科学美国人60秒，下面编在这里为为大家整理了科学美国人60秒：无声的学问相关的内容分享，希望对大家有帮助。

在托福听力考试的备考过程中，科学美国人60秒相信大家一定用得比较多，那么大家平时是如何利用这个课外资料的呢?这里小编整理了科学美国人60秒：小朋友走路更容易累的原因相关的内容分享，大家一起来学习一下吧。

科学美国人60秒听力练习：小朋友走路更容易累的原因

科学美国人60秒英文文本

A study of energy consumption among human walkers of various sizes finds that children tire more easily not due to any differences in stride style--they just need more steps to cover the same distance. Karen Hopkin reports

If you’ve ever had to pick up and carry a tired child through the mall, you know that walking sometimes tuckers out the toddlers. Now scientists think they know why. The results appear in the Journal of Experimental Biology. [P. Weyand et al., "The mass-specific energy cost of human walking is set by stature," J. Exp. Biol., link to come]

Larger animals tend to use less energy per gram of body mass than smaller ones do, even at rest. But what happens when they’re in motion? Researchers recruited walkers of different ages and sizes, from a three-foot-tall kindergartner to a six-foot adult. While the subjects logged miles on the treadmill, the scientists measured their stride and metabolism.

And they found that people pretty much walk the same way, regardless of their stature. If you scaled a five-year-old up to be six-and-a-half feet tall, the giant child would lope along just like a similarly sized adult.

What’s more, walkers of all heights use the same amount of energy per step. That means that big people don’t conserve energy by strolling in a more economical style. They expend less energy because—just as you may have always suspected—they simply need fewer strides to cover the same ground. Which means that for some people a walk in the park ain’t necessarily a walk in the park.