2019年12月英语六级考试阅读美文赏析5

同学们在备考时可以根据坦途网英语六级考试频道更新的历年真题总结出英语六级考试阅读技巧，这可以锻炼大家的归纳能力。其实美文赏析也是一样，虽然没有考题，但是也相当于一篇阅读理解，大家可以按照考试要求练习速度，对阅读理解也是有帮助的。

Evolution and Wheels

In the past, evolutionary biologists contemplating the absence of wheels in nature agreed that the explanation was not undesirability: wheels would be good for animals, just as they are for us. Animals were prevented from evolving wheels, the biologists reasoned, by the following dilemma: living cells in an animal's body are connected to the heart by blood vessels, and to the brain by nerves. Because a rotating joint is essential to a wheel, a wheel made of living cells would twist its artery vein and nerve connections at the first revolution, making living impracticable. However, there is a flaw in the argument that the evolution of wheeled animals was thwarted by the insoluble joint problem. The theory fails to explain why animals have not evolved wheels of dead tissue with no need for arteries and nerves. Countless animals, including us, bear external structures without blood supply or nerves - for example, our hair and fingernails, or the scales, claws, and ho rns of other animals. Why have rats not evolved bony wheels, similar to roller skates?Paws might be more useful than wheels in some situations, but cats' claws are retractable: why not retractable wheels?We thus arrive at the serious biological paradox flippantly termed the RRR dilemma: nature's failure to produce rats with retractable roller skates.

同学们对于今天更新的美文赏析有什么感受吗？美文阅读不仅仅是通读一遍就结束了，更多的是学习好句式的表达，思考怎么把这些优美的句子应用到作文中，并且思考有没有提高自己的阅读速度，语感有没有提升，这些都是同学们需要注意的问题，只要解决了所有问题，英语六级考试也就胜券在握了。