公共英語五級閱讀文章

　　備考公共英語五級需要一定的閱讀量，以擴(kuò)充自己的詞匯量與英語知識。下面為大家提供兩篇優(yōu)秀的公共英語五級閱讀文章。

　　公共英語五級閱讀文章一

　　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.

　　進(jìn)化與輪子

　　從前，研究自然界沒有輪子的進(jìn)化論生物學(xué)家都同意不能用無此需要來解釋這種現(xiàn)象：輪子對于動物會像對于我們?nèi)祟愐粯佑泻锰帯Ｉ�物學(xué)家們推論，動物沒有進(jìn)化出輪子是由下述困難所致：動物身上的活細(xì)胞通過血管與心臟相連，通過神經(jīng)與大腦相連。因為一個旋轉(zhuǎn)的接頭對輪子來說是至關(guān)重要的，由活的細(xì)胞構(gòu)成的輪子在第一次轉(zhuǎn)動時便會扭傷其上的動脈和神經(jīng)的連結(jié)，因而不現(xiàn)實。

　　不過，動物未能進(jìn)化出輪子是受阻于無法解決接頭問題的說法有一個缺陷。這種理論無法解釋為何動物沒有進(jìn)化出由死組織構(gòu)成的而無需動脈和神經(jīng)的`輪子。包括人在內(nèi)的無數(shù)動物都有一些沒有血液供應(yīng)和神經(jīng)的體外構(gòu)造，例如，我們的頭發(fā)和指甲，或者鱗片、爪子和其它一些動物的角。為什么老鼠沒有進(jìn)化出類似于滑輪溜冰鞋的骨質(zhì)的輪子呢?在某些情況下，爪子可能比輪子更有用，但貓的爪子是可以伸縮的：為什么不能有可以伸縮的輪 子呢?這樣，我們便得出了一個被戲稱為 RRR 的嚴(yán)肅的生物學(xué)悖論：大自然未能產(chǎn)生出有可伸縮的滑輪溜冰鞋的老鼠。

　　公共英語五級閱讀文章二

　　Population Growth

　　The growth of population during the past few centuries is no proof that population will continue to grow straight upward toward infinity and doom. On the contrary, demographic history offers evidence that population growth has not been at all constant. According to paleoecologist Edward Deevey, the past million years show three momentous changes. The first, a rapid increase in population around one m illion B. C., followed the innovations of tool making and tool using. But when the new power from the use of tools has been exploited, the rate of world population growth fell and became almost stable. The next rapid jump in population started perhaps 10,000 years ago, when mankind began to keep herds, plow and plant the earth. Once again when initial productivity gains had been absorbed, the rate of population growth abated. These two episodes suggest that the third great change, the present rapid growth, which began in the West between 250 and 350 years ago, may also slow down when, or if, technology begins to yield fewer innovations. Of course, the current knowledge revolution may continue without foreseeable end. Either way - contrary to popular belief in constant geometric growth - population can be expected in the long run to adjust to productivity. And when one takes this view, population growth is seen to represent economic progress and human triumph rather than social failure.

　　人口增長

　　以往幾個世紀(jì)人口的增長并不能證明人口會無限地直線向上增長直到毀滅的地步。相反地，人口統(tǒng)計史料證明人口的增長完全不是穩(wěn)定的。古生態(tài)學(xué)家愛德華·狄維認(rèn)為，在過去100 萬年間出現(xiàn)過3 次重大的變動。第一次在公元前 100 萬年左右，隨著在工具的制作和使用上的革新而出現(xiàn)人口迅速增長。但當(dāng)工具的使用所產(chǎn)生的新動力被充分利用以后，世界人口增長率下降并且趨于穩(wěn)定。第二次人口劇增大約始于人類開始蓄畜、墾耕的10，000 年前。一旦最初的生產(chǎn)力增長被吸收殆盡，人口的增長再次衰落。以上兩段說明，若技術(shù)革新的成果開始減少，從250 到350 年前就在西方開始出現(xiàn)的并且目前還在 繼續(xù)的人口迅速增長可能也會放慢。當(dāng)然，當(dāng)前的知識革命也許會持續(xù)下去而無法預(yù)見其 末來。無論如何，與那種認(rèn)為人口以幾何級數(shù)持續(xù)增長的觀點相反，從長遠(yuǎn)的觀點來說，人口可望受到生產(chǎn)力的調(diào)節(jié)。接受了這一觀點，人口的增長就可以被看成是經(jīng)濟(jì)進(jìn)步和人類勝利的標(biāo)志，而不是社會衰敗的標(biāo)志。

【公共英語五級閱讀文章】相關(guān)文章：

公共英語五級預(yù)測閱讀文章08-19

2017公共英語五級閱讀文章06-19

公共英語五級閱讀文章《電視》06-14

公共英語五級的閱讀文章06-14

公共英語三級閱讀文章06-19

公共英語二級閱讀文章《煉油》06-21

2017公共英語二級閱讀文章06-19

公共英語五級的閱讀文章預(yù)測08-19

公共英語五級閱讀文章《能量來源》06-23