今天给大家带来雅思阅读真题讲解相关内容，帮助大家学习和掌握雅思阅读答题的思路及技巧，今天的阅读文章是关于动物背景知识的。下面就是今天给大家带来的雅思内容：雅思阅读真题讲解附长难句练习，希望能够帮助到大家。
What Do Whales Feel?
Some of the senses that we and other terrestrial mammals take for granted are either reduced or absent in cetaceans or fail to function well in water. For example, it appears from their brain structure that toothed species are unable to smell. Baleen species, on the other hand, appear to have some related brain structures but it is not known whether these are functional. It has been speculated that, as the blowholes evolved and migrated to the top of the head, the neural pathways serving sense of smell may have been nearly all sacrificed. Similarly, although at least some cetaceans have taste buds, the nerves serving these have degenerated or are rudimentary.
The sense of touch has sometimes been described as weak too, but this view is probably mistaken. Trainers of captive dolphins and small whales often remark on their animals’ responsiveness to being touched or rubbed, and both captive and free-ranging cetacean individuals of all species (particularly adults and calves, or members of the same subgroup) appear to make frequent contact. This contact may help to maintain order within a group, and stroking or touching are part of the courtship ritual in most species. The area around the blowhole is also particularly sensitive and captive animals often object strongly to being touched there.
The sense of vision is developed to different degrees in different species. Baleen species studied at close quarters underwater – specifically a grey whale calf in captivity for a year, and free-ranging right whales and humpback whales studied and filmed off Argentina and Hawaii – have obviously tracked objects with vision under-water, and they can apparently see moderately well both in water and in air. However, the position of the eyes so restricts the field of vision in baleen whales that they probably do not have stereoscopic vision.
On the other hand, the position of the eyes in most dolphins and porpoises suggests that they have stereoscopic vision forward and downward. Eye position in freshwater dolphins, which often swim on their side or upside down while feeding, suggests that what vision they have is stereoscopic forward and upward. By comparison, the bottlenose dolphin has extremely keen vision in water. Judging from the way it watches and tracks airborne flying fish, it can apparently see fairly well through the air–water interface as well. And although preliminary experimental evidence suggests that their in-air vision is poor, the accuracy with which dolphins leap high to take small fish out of a trainer’s hand provides anecdotal evidence to the contrary.
Such variation can no doubt be explained with reference to the habitats in which individual species have developed. For example, vision is obviously more useful to species inhabiting clear open waters than to those living in turbid rivers and flooded plains. The South American boutu and Chinese beiji, for instance, appear to have very limited vision, and the Indian susus are blind, their eyes reduced to slits that probably allow them to sense only the direction and intensity of light.
Although the senses of taste and smell appear to have deteriorated, and vision in water appears to be uncertain, such weaknesses are more than compensated for by cetaceans’ well-developed acoustic sense. Most species are highly vocal, although they vary in the range of sounds they produce, and many forage for food using echolocation. Large baleen whales primarily use the lower frequencies and are often limited in their repertoire. Notable exceptions are the nearly song-like choruses of bowhead whales in summer and the complex, haunting utterances of the humpback whales. Toothed species in general employ more of the frequency spectrum, and produce a wider variety of sounds, than baleen species (though the sperm whale apparently produces a monotonous series of high-energy clicks and little else). Some of the more complicated sounds are clearly communicative, although what role they may play in the social life and ‘culture’ of cetaceans has been more the subject of wild speculation than of solid science.
真题讲解：
长难句练习：
1. Trainers of captive dolphins and small whales often remark on their animals' responsiveness to being touched or rubbed, and both captive and freeranging cetacean individuals of all species (particularly adults and calves, or members of the same subgroup)
参考译文：训练者捕获海豚和小鲸鱼经常评论它们的动物反映当被抚摸或是摩擦的时候，并且无论是捕获还是放养的所有种类的鲸类个体(尤其是成年鲸和幼仔，或是用一个子群中的成员)表现出频繁的接触。
2. By comparison, the bottlenose dolphin has extremely keen vision in water. From the way it watches and tracks airborne flying fish, it can apparently see fairly well through the air-water interface as well.
参考译文：相反的是，宽吻海豚在水中视力就很敏锐，而从它观察及追踪空中飞鱼的方式来看，它在水天交界面的视力也相当好。
知识点：现在分词做原因状语
1)主语要一致：分词短语的逻辑主语与句子主语要一致
2)独立分词结构：有时候分词的动作与谓语动作不是同一主语发出的，这时分词可以带上自己的逻辑主语，就形成了“名词/代词+分词短语”的结构，即所谓的独立分词结构。例如It being so nice a day, we go out for a walk.
3. Although the senses of taste and smell appear to have deteriorated, and vision in water appears to be uncertain, such weaknesses are more than compensated for by cetaceans’ well-developed acoustic sense.”
参考译文：尽管鲸鱼的味觉和嗅觉严重衰退，在水中的视觉又不那么确定，然而这些缺陷完全可以被他们那高度发达的听觉系统所弥补。
知识点：more than的用法
1.在口语当中，more than通常表示“极其;非常”。
2.More than 还有“超出;超过”的意思。
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