GRE阅读笔记NO6-1

GRE阅读笔记新东方绝密资料

A mysterious phenomenon is the ability of SE

over-water migrants to travel on course. Birds,

bees, and other species can keep track of time

without any sensory cues from the outside ⊙

world, and such “biological clocks” clearly con- SE

tribute to their “compass sense.” For example, 促进

they can use the position of the Sun or stars,

along with the time of day, to find north. But 转折

compass sense alone cannot explain how birds ∨

navigate the ocean: after a flock traveling east is

blown far south by a storm, it will assume the

proper northeasterly course to compensate. Per-

haps, some scientists thought, migrants deter- SE

mine their geographic position on Earth by ce-

lestial navigation, almost as human navigators

use stars and planets, but this would demand of SE

the animals a fantastic map sense. Researchers —

now know that some species have a magnetic

sense, which might allow migrants to determine

their geographic location by detecting variations

in the strength of the Earth’s magnetic field.

文章结构类型：解释针对问题性文章。文章首句提出一个有待阐述的现象，然后提出了一种

“罗盘效应”的解释，然后否定了此解释，又提出了“天体导航”的解释，然后又否定了这

种解释，最后作者提出了“磁场感应”的解释，认为它有可能成为有效的解释。

准TS：（无TS）But this would demand of the animals a fantastic map sense. Researchers now know that some species have a magnetic sense.

单词：

阅读专用词汇：fantastic，phenomenon

积累专业词汇：biological clock, celestial navigation, magnetic

在水面上空迁移的动物能够沿着正确方向飞行，这实乃一种神秘莫测的现象。鸟类、蜜蜂、以及其它动物

种类可以追踪时辰，而不必依赖于来自外界的任何感觉醒示物，这样的“生物钟”（biological clock）显

然促进了其“方位感”（compass sense）。例如，它们可利用太阳或星辰的位置，连同白昼的时辰，来寻找

到北方这一方位。但是，方位感本身不足以解释鸟类是如何在海洋上空导航的：当一群东飞的候鸟被暴风

雨吹向偏南方之后，这群鸟会采取适度的东北方向以补偿误差。某些科学家认为，或许，迁移动物是通过

天体导航（celestial navigation）来确定其在地球上的地理位置，几乎如同人类航海家利用星辰和行星那样；

但这将要求动物具有一种难于令人置信的地图感（mapsense）。科研人员现在获悉，某些动物种类具备一种

磁感（magnetic sense），这可能允许动物通过测定地球磁场强度变化而确立其地理位置。

17. The main idea of the passage is that （主旨题）

(A) migration over land requires a simpler explanation than migration over water does (细节，

无端比较)

(B) the means by which animals migrate over water are complex and only partly understood（综

合TS、SE可知）

(C) the ability of migrant animals to keep track of time is related to their magnetic sense

（“compass sense.”定位L2~6，Birds, bees, and other species can keep track of time without any