很多人都认为，体型大的动物消耗更多的能量。但一项研究表明事实并非如此。

　　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 Biol**y. [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 l**ged 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.

随着科技的发展，托福来到了第二阶段cbt-computer based test 也就是机考满分为300，托福的考试应用的的范围越来越广，托福也趋向于成熟，ibt-internet based test网考新托福孕育而生满分为120分，现在仍然有一些大学或者事业单位内部仍采用老托福纸考，但是申请大学或高中被官方普遍承认的只是新托福，新托福比以往的老托福能够更加精准的测出考生的水平，不像老托福，靠刷题或者死记硬背一些技巧就能提分托福考试衡量口语比其它考试更加公正，因为托福考试采用多人评分方式, 不像其它考试只使用一人评分，托福考试使考生更轻松地参与口语考试环节, 因为与其他英语考试相比, 它消除了受试者的恐惧心理, 同时可以提供更为客观的分数，享受美国的优质高校资源，申请美国留学托福成绩是硬指标, 无论是出国读硕士，还是本科,还是出国读高中, 美国留学托福成绩很重要, 该成绩比GRE、SAT的成绩更重要。雅思考试, 让你通行全球，全球超过8,000所机构认可雅思成绩，适用留学、移民、就业;适用英国、澳大利亚、新西兰、美国、加拿大, 及荷兰、法国、德国、瑞士、瑞典、新加坡、香港、马来西亚、日本、南非等*，全球英语测评领导者, 你值得信赖的英语考试，雅思考试由在英语测评方面拥有95年悠久历史和丰富经验的剑桥大学考试委员会研发, 首创从听、说、读、写四方面进行英语全面考核。