雅思练习总结（二十五）

雅思练习总结（二十五）

本文章是雅思练习总结（二十五），总结了文章《Let’s Go Bats》，内容包括原文精翻，文章脉络总结，单词扩展学习3个部分

1 文章原文及翻译

Let’s Go Bats

翻译：蝙蝠，冲冲冲！

A
Bats have a problem: how to find their way around in the dark. They hunt at night, and cannot use light to help them find prey and avoid obstacles. You might say that this is a problem of their own making, one that they could avoid simply by changing their habits and hunting by day. But the daytime economy is already heavily exploited by other creatures such as birds. Given that there is a living to be made at night, and given that alternative daytime trades are thoroughly occupied, natural selection has favoured bats that make a go of the night-hunting trade. It is probable that the nocturnal trades go way back in the ancestry of all mammals. In the time when the dinosaurs dominated the daytime economy, our mammalian ancestors probably only managed to survive at all because they found ways of scraping a living at night. Only after the mysterious mass extinction of the dinosaurs about 65 million years ago were our ancestors able to emerge into the daylight in any substantial numbers.

翻译：蝙蝠身上有个秘密：他们是如何在黑暗中寻找出路的呢？它们在夜间捕猎，按理来说是无法利用光线帮助它们找到猎物并避开障碍物。你可能会说，这是蝙蝠自作自受。它们改变习惯，在白天捕猎，不就可以解决了嘛（何不食肉糜，哈哈哈哈）。但白天经济已被鸟类等其他生物大量利用。鉴于白天已经完全被占用，受自然选择青睐的蝙蝠就可以在夜间这个蓝海开展捕猎活动了。在夜间捕猎可以追溯到所有哺乳动物的祖先。在恐龙主宰白天经济的时代，我们的哺乳动物祖先可能就是因为他们找到了在夜间勉强谋生的方法才得以幸存。直到大约 6500 万年前恐龙神秘大规模灭绝之后，我们的祖先才能够在白天捕猎。

B
Bats have an engineering problem: how to find their way and find their prey in the absence of light. Bats are not the only creatures to face this difficulty today. Obviously the night-flying insects that they prey on must find their way about somehow. Deep-sea fish and whales have little or no light by day or by night. Fish and dolphins that live in extremely muddy water cannot see because, although there is light, it is obstructed and scattered by the dirt in the water. Plenty of other modern animals make their living in conditions where seeing is difficult or impossible.

翻译：蝙蝠身上还有一个工程学谜团：如何在没有光的情况下寻路并找到猎物。但是蝙蝠并不是当今唯一面临这一困难的生物。显然，蝙蝠们的猎物夜行昆虫必须以某种方式找到路。无论日夜，深海鱼和鲸鱼都见不到光。生活在极其浑浊的水中鱼类和海豚也无法看见，因为尽管有光，但光会被水中的污垢阻挡和散射。许多其他现代动物都在视力困难或无法看见的环境中生存。

C
Given the questions of how to manoeuvre in the dark, what solutions might an engineer consider? The first one that might occur to him is to manufacture light, to use a lantern or a searchlight. Fireflies and some fish (usually with the help of bacteria) have the power to manufacture their own light, but the process seems to consume a large amount of energy. Fireflies use their light for attracting mates. This doesn’t require a prohibitive amount of energy: a male’s tiny pinprick of light can be seen by a female from some distance on a dark night, since her eyes are exposed directly to the light source itself. However, using light to find one’s own way around requires vastly more energy, since the eyes have to detect the tiny fraction of the light that bounces off each part of the scene. The light source must therefore be immensely brighter if it is to be used as a headlight to illuminate the path, than if it is to be used as a signal to others. In any event, whether or not the reason is the energy expense, it seems to be the case that, with the possible exception of some weird deep-sea fish, no animal apart from man uses manufactured light to find its way about.

翻译：面对如何在黑暗中行进的问题，一个工程师会考虑哪些解决方案呢？他首先想到的可能是制造光，比如使用灯笼或探照灯。萤火虫和一些鱼（通常在细菌的帮助下）有能力制造自己的光，但这个过程似乎消耗了大量的能量。萤火虫利用它们的光来吸引配偶。这并不需要过多的能量：在漆黑的夜晚，雌性可以从远处看到雄性发出的微小光点，因为她的眼睛直接暴露在光源本身下。然而，利用光来寻找自己的路需要更多的能量，因为眼睛必须检测从场景的每个部分反射的微小部分光。因此，如果要将光源用作照亮道路的前灯，那么光源必须比用作向其他物体发出信号时更亮。无论如何，不​​管原因是否在于能量消耗，似乎除了一些奇怪的深海鱼外，没有任何动物会利用人造光来寻找路径。

D
What else might the engineer think of? Well, blind humans sometimes seem to have an uncanny sense of obstacles in their path. It has been given the name ‘facial vision’, because blind people have reported that it feels a bit like the sense of touch, on the face. One report tells of a totally blind boy who could ride his tricycle at good speed round the block near his home, using facial vision. Experiments showed that, in fact, facial vision is nothing to do with touch or the front of the face, although the sensation may be referred to the front of the face, like the referred pain in a phantom limb. The sensation of facial vision, it turns out, really goes in through the ears. Blind people, without even being aware of the fact, are actually using echoes of their own footsteps and of other sounds, to sense the presence of obstacles. Before this was discovered, engineers had already built instruments to exploit the principle, for example to measure the depth of the sea under a ship. After this technique had been invented, it was only a matter of time before weapons designers adapted it for the detection of submarines. Both sides in the Second world war relied heavily on these devices, under such codenames as Asdic (British) and Sonar (American), as well as Radar (American) or RDF (British), which uses radio echoes rather than sound echoes.

翻译：一位工程师还能想到什么呢？盲人有时似乎对路上的障碍物有一种不可思议的感觉。这种感觉被称为“面部视觉”，因为盲人报告说，这种感觉有点像脸部的触觉。一份报告讲述了一个完全失明的男孩，他能利用面部视觉以很快的速度骑着三轮车绕着家附近的街区转一圈。实验表明，面部视觉实际上与触觉或脸部前方无关，尽管这种感觉可能与脸部前方有关，就像幻肢中的牵涉痛一样。事实证明，面部视觉的感觉实际上是通过耳朵进入的。盲人甚至没有意识到这一点，实际上是在利用他们自己的脚步声和其他声音的回声来感知障碍物的存在。在发现这一点之前，工程师们已经制造了利用这一原理的仪器，例如测量船底的海水深度。在这项技术发明之后，武器设计师将其用于探测潜艇只是时间问题。第二次世界大战中交战双方都严重依赖这些设备，其代号包括 Asdic（英国）和 Sonar（美国），以及 Radar（美国）或 RDF（英国），后者使用无线电回声而不是声音回声。

E
The Sonar and Radar pioneers didn’t know it then, but all the world now knows that bats, or rather natural selection working on bats, had perfected the system tens of millions of years earlier, and their ‘radar’ achieves feats of detection and navigation that would strike an engineer dumb with admiration. It is technically incorrect to talk about bat ‘radar’, since they do not use radio waves. It is sonar. But the underlying mathematical theories of radar and sonar are very similar, and much of our scientific understanding of the details of what bats are doing has come from applying radar theory to them. The American zoologist Donald Griffin, who was largely responsible for the discovery of sonar in bats, coined the term ‘echolocation’ to cover both sonar and radar, whether used by animals or by human instruments.

翻译：声纳和雷达的先驱们当时并不知道，但现在全世界都知道，蝙蝠，或者说自然选择在蝙蝠身上起作用，早在数千万年前就完善了该系统，它们的“雷达”具备的探测和导航技术让工程师们震撼得哑口无言。从技术上讲，将蝙蝠的感知系统称为“雷达”是不正确的，因为它们不使用无线电波。它是声纳。但雷达和声纳的底层数学理论非常相似，我们对蝙蝠行为细节的科学理解大部分来自于将雷达理论应用于蝙蝠。美国动物学家唐纳德·格里芬 (Donald Griffin) 对蝙蝠声纳的发现有重大贡献，他创造了“回声定位”一词来涵盖声纳和雷达，无论是动物使用的还是人类仪器使用的。

2 文章结构分析

这篇文章挺有意思的，有点像英文的科技趣话，内容总结如下：

1. A段以问句开头：蝙蝠是如何在黑暗中寻找出路的呢？后面就开始介绍了，蝙蝠在夜间出没，一是因为白天竞争太激烈了，就像远古时期的恐龙霸占白天，人类祖先也很有可能是找到了在夜间捕猎的方法，才能存活的；二是老天爷赏饭吃，蝙蝠有特殊的天赋让他们能够在黑夜出没

2. B段也是一问句开头，这次是探究蝙蝠如何在没有光的情况下寻路并找到猎物。这里没有直接说原因，而是先说了其他面对同样问题的生物的解决方案，比如深海鱼、鲸鱼、海豚等生物。

3. C段还是在卖关子：人类工程师会如何解决黑夜中的捕猎问题呢？答案是自造光源。虽然部分生物，如萤火虫和部分鱼类（通常在细菌的帮助下）可以自造光源，但制造光源、观测光源需要消耗很多能量，所以也不太可取。而且不​​管原因是否在于能量消耗，似乎除了一些奇怪的深海鱼外，没有任何动物会利用人造光来寻找路径。

4. D段还是在吊胃口，那还有没有什么其他可能性呢？有些盲人称，他们会有一些脸部的触觉，这种感觉被称为“面部视觉”，一个完全失明的男孩，他能利用面部视觉以很快的速度骑着三轮车绕着家附近的街区转一圈。但是研究表明，这种面部视觉与触觉或脸部的朝向无关，它实际是进入了盲人的耳部，这种技术在二战时，被用于探测潜艇。

5. E段给出了答案，制造着声呐和雷达的先驱们恐怕是不知道，蝙蝠的生物感知系统，就是声呐，而声呐和雷达的底层数学理论非常相似。对蝙蝠感知机制的研究具有重要贡献的动物学家，唐纳德·格里芬 (Donald Griffin) 创造了“回声定位”一词来涵盖声纳和雷达，无论是动物使用的还是人类仪器使用的

文章整体结构如下