GRE阅读练习：鸟类磁性感知能力新发现.docxVIP

Word文档下载后（可任意编辑） 第 第 PAGE 1 页 共 NUMPAGES 1 页 GRE阅读练习：鸟类磁性感知能力新发现 GRE阅读文章：GRE阅读练习：鸟类磁性感知能力新发现 GRE考试精品课程训练  WHERE would people be without magnetic compasses?  人类没有指南针会怎样?  The short answer is: lost.  很简单：迷失方向。  By giving human beings a sixth sense—an ability to detect the hitherto invisible magnetic field of the Earth—the compass proved one of the most important inventions ever.  指南针给了人类第6感，使人能辨别地球无形的磁场，成为最重要的发明之一。  It let sailors navigate without sight of the night sky.  海员不用观察夜空便可以辨识方向。  And that led to the voyages of discovery, trade and conquest which created the political geography of the modern world.  人们用它进行海上探索，海上交易，攻城掠地，进而开创了现代世界的政治版图。  Imagine, then, what animals which had their own, built-in compasses could achieve.  有些动物有自己内嵌的指南系统。可以想象得出这些动物的能力。  They might spend their summers doing the English Season in Glyndebourne or Henley, and then overwinter in the warmth of Mombasa.  它们可以在戈林德伯恩或亨利镇消暑，享受自己的英格兰夏日。然后在温暖的蒙巴萨岛过冬。  They might strike out, like intrepid pioneers, from Angola to Anchorage.  它们可以像无畏的开拓者一样，从安哥拉独闯安克雷奇。  They might even, if truly gripped by wanderlust and a hatred of the darkness, live in near-perpetual daylight by migrating from Pole to Pole.  假如它们为旅行所牵绊，为黑暗而烦恼，它们会穿梭于两极之间，过着永远有光亮的生活。  And that is just what some birds do.  以上这些只是鸟类能力的一部分。  Swallows travel between Europe and Africa. Northern wheatears fly from Africa to Alaska, and back.  家燕在欧洲和非洲之间迁徙。石栖鸟在非洲和阿拉斯加之间迁徙。  Arctic terns each year make the journey from one end of the planet to the other.  每年，北极燕鸥都会从地球的一端飞到另一端。  And they can do it, at least in part, because they do have a magnetic sense denied to humans.  它们能这么做的原因之一便是鸟类可以感知磁性，而人类不行。  The most familiar avian navigation trick is that pulled off by homing pigeons.  人类最为熟知的鸟类导航技巧就是通过研究信鸽而得到的。  As a consequence pigeons have often found themselves at the sharp end of investigations about how bird navigation in gen