The human criterion for perfect vision is 20/20 for reading the standard lines on a Snellen eye chart without a hitch. The score is determined by how well you read lines of letters of different sizes from 20 feet away. But being able to read the bottom line on the eye chart does not mean approximate perfection as far as other species are concerned. Most birds would consider us very visually handicapped. The hawk, for instance, has such sharp eyes that it can spot a dime on the sidewalk while perched on top of the Empire State Building. It can make fine visual distinctions because it is blessed with one million cones per square millimeter in its retina （视网膜）.And in water, humans are farsighted, while the
kingfisher, swooping down to spear fish, can see well in both the air and water because it is endowed with two foveae （凹窝） areas of the eye, consisting mostly of cones that provide visual distinctions. One fovea permits the bird, while in the air, to scan the water below with one eye at a time. This is called monocular vision. Once it hits the water, the other fovea joins in, allowing the kingfisher to focus both eyes, like binoculars, on its prey at the same time. A frog’s vision is distinguished by its ability to perceive things as a constant motion picture. Known as “bug detectors”, a highly developed set of cells in a frog’s eyes responds mainly to moving objects. So, it is said that a frog sitting in a field of dead bugs wouldn’t see them as food and would starve.
The bee has a “compound” eye, which is used for navigation. It has 15,000 facets that divide what it sees into a pattern of dots or mosaic. With this kind of vision, the bee sees the sun only as a single dot, a constant point of reference. Thus, the eye is a superb navigational instrument that constantly measures the angle of its line of flight in relation to the sun. A bee’s eye also gauges flight speed. And if that is not enough to leave our 20/20 “perfect vision” paling into insignificance, the bee is capable of seeing something we can’t—ultraviolet light. Thus, what humans consider to be “perfect vision” is in fact rather limited when we look at other species. However, there is still much to be said for the human eye. Of all the mammals, only humans and some primates can enjoy the pleasures of color vision.
1.The Snellen eye chart measures one’s eyesight by（ ）.
2.How is hawk’s eyesight better than ours?
3.Monocular vision enables the kingfisher to（ ）.
4.A bee finds its direction by（ ）.
5.What is the main idea of the passage?
问题1选项
A.The Snellen eye chart measures one’s eyesight by the number of lines he reads
B.the distance he stands away from the chart
C.the speed at which he recognizes the letters
D.several integrative factors
问题2选项
A.It can identify small items more quickly than we do.
B.It can see at a longer distance than we do.
C.It has more cones in the retina than we do.
D.It has bigger eyes than we do.
问题3选项
A.avoid farsightedness
B.be able to see underwater
C.move one eye at a time
D.focus its eyes on the prey
问题4选项
A.dividing what it sees into thousands of dots
B.constantly gauging its flying speed
C.using the sun as a constant point of reference
D.measuring the angle of the sun
问题5选项
A.The differences between human eyes and other species’ eyes.
B.The advantages of other species’ eyes in comparison with human eyes.
C.The factors that make other species’ eyes better than human eyes.
D.The standard that determines the “perfect vision” of human eyes.
第1题:A
第2题:B
第3题:C
第4题:C
第5题:A
第1题:
【选项释义】
The Snellen eye chart measures one’s eyesight by ________. 斯内伦视力表通过________检测一个人的视力。
A. the number of lines he reads A. 他阅读的行数
B. the distance he stands away from the chart B. 他离视力表的距离
C. the speed at which he recognizes the letters C. 他识别字母的速度
D. several integrative factors D. 一些综合的因素
【考查点】事实细节题。
【解题思路】根据题干关键词The Snellen eye chart可以定位到原文第一段第一二句The human criterion for perfect vision is 20/20 for reading the standard lines on a Snellen eye chart without a hitch. The score is determined by how well you read lines of letters of different sizes from 20 feet away.（判断人的视力是否完好的标准是看斯内伦视力表的时候，是否能毫无障碍地达到20/20的视力。测试值取决于从20英尺之外，你能看到多少行大小不一的字母。），由此可知，斯内伦视力表是通过看到的行数来测试的，因此A选项“他阅读的行数”正确。
【干扰项排除】
B选项“他离视力表的距离”，原文第一段第二句from 20 feet away（20英尺之外），由此可知离视力表的距离是固定的，并不能反映一个人的视力，属于曲解原文；
C选项“他识别字母的速度”，D选项“一些综合的因素”文中并没有提到，属于无中生有。
第2题:
【选项释义】
How is hawk’s eyesight better than ours? 猫头鹰的视力如何比人类的更好？
A. It can identify small items more quickly than we do. A. 它识别物体的速度比我们快。
B. It can see at a longer distance than we do. B. 它能从更远的距离看东西。
C. It has more cones in the retina than we do. C. 它视网膜上的视锥细胞比我们多。
D. It has bigger eyes than we do. D. 它的眼睛比我们更大。
【考查点】事实细节题。
【解题思路】根据题干关键词hawk’s eyesight可以定位到原文第一段第四句The hawk, for instance, has such sharp eyes that it can spot a dime on the sidewalk while perched on top of the Empire State Building.（猫头鹰的视力非常敏锐，当它在帝国大厦的顶层时，它能看清在人行道上的一角硬币。），由此可知，猫头鹰能从很远的距离看东西，因此B选项“它能从更远的距离看东西”正确。
【干扰项排除】
A选项“它识别物体的速度比我们快”，原文中没有提到，属于无中生有；
C选项“它视网膜上的视锥细胞比我们多”，原文第一段第四句It can make fine visual distinctions because it is blessed with one million cones per square millimeter in its retina.（它有这么好的远距离视力是因为它视网膜上有更多的视锥细胞），作者解释了猫头鹰能从更远看东西的原因，并不是它视力比我们好的体现，属于张冠李戴；
D选项“它的眼睛比我们更大”，文中并没有提到，属于无中生有。
第3题:
【选项释义】
Monocular vision enables the kingfisher to ________. 单眼视觉让翠鸟能够________。
A. avoid farsightedness A. 避免远视
B. be able to see underwater B. 能在水下看东西
C. move one eye at a time C. 一次移动一只眼睛
D. focus its eyes on the prey D. 眼睛盯住猎物
【考查点】事实细节题。
【解题思路】根据题干关键词Monocular vision可以定位到原文第一段第六第七句One fovea permits the bird, while in the air, to scan the water below with one eye at a time. This is called monocular vision.（一个中央窝让飞翔在空中的翠鸟每次用一只眼睛扫视水下情况。这被称为单眼视觉。），由此可知，单眼视觉是让翠鸟一次只用一只眼睛看东西，因此C选项“一次移动一只眼睛”正确。
【干扰项排除】
A选项“避免远视”，原文中提到And in water, humans are farsighted, while the kingfisher, swooping down to spear fish, can see well in both the air and water（在水下，人类是远视的，但是翠鸟俯冲下来刺鱼时，在水中的视力跟在空中一样好），人类在水下是远视的，但是文中并没有翠鸟是否远视，更没有表明是单眼视觉让翠鸟避免远视，属于曲解原文；
B选项“能从水下看东西”，原文第一段第六句中to scan the water below（扫视水下情况），而题干be able to see underwater是指在水下看东西，属于曲解原文；
D选项“眼睛盯住猎物”文中并没有提到，属于无中生有。
第4题:
【选项释义】
A bee finds its direction by ________. 蜜蜂能通过________来辨别方向。
A. dividing what it sees into thousands of dots A. 把看到的东西分成成千上万个点
B. constantly gauging its flying speed B. 不断测量它的飞行速度
C. using the sun as a constant point of reference C. 把太阳作为一个恒定的参考点
D. measuring the angle of the sun D. 测量太阳的角度
【考查点】事实细节题。
【解题思路】根据题干关键词A bee和direction可以定位到原文前四句话The bee has a “compound” eye, which is used for navigation. It has 15,000 facets that divide what it sees into a pattern of dots or mosaic. With this kind of vision, the bee sees the sun only as a single dot, a constant point of reference. Thus, the eye is a superb navigational instrument that constantly measures the angle of its line of flight in relation to the sun.（蜜蜂有用来导航的“复合”眼。它有1500个小平面，能够把看到的东西分成点或者马赛克的图案。有了这种视觉，蜜蜂只把太阳看做一个单点，一个不变的参考点。因此，眼睛是一种极好的导航仪器，它能够测量飞行路线相对于太阳的角度。）由此可知，眼睛能为蜜蜂导航（即辨别方向）的原因是因为它把太阳作为一个不变的参考点，因此C选项“把太阳作为一个恒定的参考点”正确。
【干扰项排除】
A选项“把看到的东西分成成千上万个点”，是能够把太阳作为一个恒定参考点的原因，并不是辨别方向的原因，属于张冠李戴；
B选项“不断测量它的飞行速度”，原文第二段第五句A bee’s eye also gauges flight speed.（蜜蜂的眼睛也能测量飞行速度）中的also表明，测量飞行速度与辨别方向是并列关系，并不是因果关系，属于曲解原文；
D选项“测量太阳的角度”，原文第二段第四句measures the angle of its line of flight in relation to the sun（测量飞行路线相对于太阳的角度），并不是直接测量太阳的角度，属于曲解原文。
第5题:
【选项释义】
What is the main idea of the passage? 这篇文章的主旨是什么？
A. The differences between human eyes and other species’ eyes. A. 人眼与其他物种的眼睛的区别
B. The advantages of other species’ eyes in comparison with human eyes. B. 其他物种的眼睛相对于人眼的优势
C. The factors that make other species’ eyes better than human eyes. C. 其他物种的眼睛优于人眼的因素
D. The standard that determines the “perfect vision” of human eyes. D. 人眼的视力的标准
【考查点】主旨大意题。
【解题思路】结合全文内容，原文第一段第三句But being able to read the bottom line on the eye chart does not mean approximate perfection as far as other species are concerned.（但是，能够阅读视力表最后一行在其他物种眼里，并不代表接近完美的视力。），第一段表明了其他物种眼睛的优势并且举例说明。第二段最后一句However, there is still much to be said for the human eye. Of all the mammals, only humans and some primates can enjoy the pleasures of color vision.（然而，关于人眼还有很多要说的。所有的哺乳动物，只有人类和一些灵长类生物才能享受色觉的快乐），表明人眼优于其他物种眼睛的优势，因此全文在对比人眼和其他生物眼睛的区别，因此A选项“人眼与其他物种的眼睛的区别”正确。
【干扰项排除】
B选项“其他物种的眼睛相对于人眼的优势”，C选项“其他物种的眼睛优于人眼的因素”，第二段最后一句表明人眼能享受色觉的快乐，这是人眼相对于其他物种眼睛的优势，均属于以偏概全；
D选项“人眼的视力的标准”，只在第一段第一句提到，其他内容都是在对比人眼与其他物种的眼睛，属于以偏概全。
