首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Animals on the Move A)It looked like a scene from "Jaws" but without the dramatic music. A huge shark was lowly swimming thro
Animals on the Move A)It looked like a scene from "Jaws" but without the dramatic music. A huge shark was lowly swimming thro
admin
2018-02-08
34
问题
Animals on the Move
A)It looked like a scene from "Jaws" but without the dramatic music. A huge shark was lowly swimming through the water, its tail swinging back and forth like the pendulum of a clock.
B)Suddenly sensitive nerve ending in the shark’s skin picked up vibrations of a struggling fish. The shark was immediately transformed into a deadly, efficient machine of death. With muscles taut, the shark knifed through the water at a rapid speed. In a flash the shark caught its victim, a large fish, in its powerful jaws. Then, jerking its head back and forth, the shark tore huge chunks of flesh from its victim and swallowed them. Soon the action was over.
Moving to Survive
C)In pursuing its prey, the shark demonstrated in a dramatic way the important role of movement, or locomotion, in animals.
D)Like the shark, most animals use movement to find food. They also use locomotion to escape enemies, find a mate, and explore new territories. The methods of locomotion include crawling, hopping, slithering, flying, swimming, or walking.
E)Humans have the added advantage of using their various inventions to move about in just about any kind of environment. Automobiles, rockets, and submarines transport humans from deep oceans to as far away as the moon. However, for other animals movement came about naturally through millions of years of evolution. One of the most successful examples of animal locomotion is that of the shark. Its ability to quickly zero in on its prey has always impressed scientists. But it took a detailed study by Duke University marine biologists S. A. Wainwright, F. Vosburgh, and J. H. Hebrank to find out how the sharks did it. In their study the scientists observed sharks swimming in a tank at Marine land in Saint Augustine, Fla. Movies were taken of the sharks’ movements and analyzed. Studies were also made of shark skin and muscle.
Skin Is the Key
F)The biologists discovered that the skin of the shark is the key to the animal’s high efficiency in swimming through the water. The skin contains many fibers that crisscross like the inside of a belted radial tire. The fibers are called collagen fibers. These fibers can either store or release large amounts of energy depending on whether the fibers are relaxed or taut. When the fibers are stretched, energy is stored in them the way energy is stored in the string of a bow when pulled tight. When the energy is released, the fibers become relaxed.
G)The Duke University biologists have found that the greatest stretching occurs where the shark bends its body while swimming. During the body’s back and forth motion, fibers along the outside part of the bending body stretch greatly. Much potential energy is stored in the fibers. This energy is released when the shark’ s body snaps back the other way.
H)As energy is alternately stored and released on both sides of the animal’s body, the tail whips strongly back and forth. This whip-like action propels the animal through the water like a living bullet.
Source of Energy
I)What causes the fibers to store so much energy? In finding the answer the Duke University scientists learned that the shark’ s similarity to a belted radial tire doesn’ t stop with the skin. Just as a radial tire is inflated by pressure, so, too, is the area just under the shark’s collagen "radials". Instead of air pressure, however, the pressure in the shark may be due to the force of the blood pressing on the collagen fibers.
J)When the shark swims slowly, the pressure on the fibers is relatively low. The fibers are more relaxed, and the shark is able to bend its body at sharp angles. The animal swims this way when looking around for food or just swimming. However, when the shark detects an important food source, some fantastic involuntary changes take place.
K)The pressure inside the animal may increase by 10 times. This pressure change greatly stretches the fibers, enabling much energy to be stored.
L)This energy is then transferred to the tail, and the shark is off. The rest of the story is predictable.
Dolphin Has Speed Record
M)Another fastmarine animal is the dolphin. This seagoing mammal has been clocked at speeds of 32 kilometers(20 miles)an hour. Biologists studying the dolphin have discovered that, like the shark, the animal’ s efficient locomotion can be traced to its skin. A dolphin’ s skin is made up in such a way that it offers very little resistance to the water flowing over it. Normally when a fish or other object moves slowly through the water, the water flows smoothly past the body. This smooth flow is known as laminar flow. However, at faster speeds the water becomes more turbulent along the moving fish. This turbulence muses friction and slows the fish down.
N)In a dolphin the skin is so flexible that it bends and yields to the waviness of the water.
O)The waves, in effect, become tucked into the skin’s folds. This allows the rest of the water to move smoothly by in a laminar flow. Where other animals would be slowed by turbulent water at rapid speeds, the dolphin can race through the water at record breaking speeds.
Other Animals Less Efficient
P)Not all animals move as efficiently as sharks and dolphins. Perhaps the greatest loser in locomotion efficiency is the slug. The slug(鼻涕虫), which looks like a snail without a shell, lays down a slimy(黏滑的)trail over which it crawls. It uses so much energy producing the slimy mucus(黏液)and crawling over it that a mouse traveling the same distance uses only one twelfth as much energy.
Q)Scientists say that because of the slug’s inefficient use of energy, its lifestyle must be restricted. That is, the animals are forced to confine themselves to small areas for obtaining food and finding proper living conditions. Have humans ever been faced with this kind of problem?
The high efficiency in swimming of sharks largely dues to its skin.
选项
答案
F
解析
信息明示题。题干:鲨鱼能够高效游泳主要是因为它的皮肤。题干关键词是high efficiency in swimming和largely dues to its skin。F段提到The biologists discovered that the skin of the shark is the key to the animal’s high efficiency in swimming through the water.与题干吻合,故选F。
转载请注明原文地址:https://kaotiyun.com/show/Lra7777K
0
大学英语四级
相关试题推荐
A、BecauseLondontaxidriversallhavegonethroughaverytoughtrainingperiodtogetspecialtaxidrivinglicense.B、Because
A、Becausefoxeskillfarmanimals.B、Becausefoxeslookjustlikefarmdogs.C、Becausefoxesareverycunning.D、Becausefoxesm
A、At5p.m.B、Tomorrow.C、At5o’clock.D、Inafewminutes.D细节题。题目问的是男士什么时候取回他的手表。对话中女士说下午五点钟可以吗,男士回答说恐怕不行,得明天了,然后女士说,那这样的话我现在就
A、Theideaofrealaid.B、Theaidisnotenough.C、Debtistooheavy.D、Themisuseoftheterm"aid".D细节题。文中提到:援助失败不是他们的初衷,他的错误
A、Ithadbeenstolenbysomeone.B、Ithadbeenmovedtothenextblock.C、Ithadbeenparkedatawrongplace.D、Ithadbeentak
A、Lackofresources.B、Shortageoffunding.C、Transportproblems.D、Poormanagement.C从选项关键词lack,shortage,problem,poor推测是问某种负面问题
Divorcedoesn’tnecessarilymakeadultshappy.Buttoughingitoutinanunhappymarriageuntilitturnsaroundjustmightdo,a
Inthe1960s,medicalresearchersThomasHolmesandRichardRahedevelopedachecklistofstressfulevents.Theyappreciatedthe
Divorcedoesn’tnecessarilymakeadultshappy.Buttoughingitoutinanunhappymarriageuntilitturnsaroundjustmightdo,a
A、64percent.B、60percent.C、46percent.D、44percent.A本题考查对新闻细节(数字)的捕捉。新闻中提到“expertssaysince1900,64percentofwetlandshav
随机试题
工作接地是将电气设备的金属外壳与接地装置之间的可靠连接。 ()
七条眼外肌中,最长的是:
患者,男,22岁。下腰部疼痛不适1年余,逐渐加重,经休息不能缓解。伴有双侧跟骨结节肿痛。行X线片检查后,临床医师要求再行骶髂关节CT检查,其目的在于1.提供骶髂关节准确的解剖学情况2.显示X线片未发现的细小骨质破坏3.了解有无骶髂关节软骨下骨囊变
任何商品的替代效应总为负值。()[2009年考题]
公路路线通过地震动峰值加速度为()地区时,应进行强震区工程地质勘察。
当用户使用相同的操作员姓名登录,并对其编制的凭证进行审核时,系统会()。
单位组织迎新座谈会,需要采购一些水果,领导暗示你到他的一位朋友那里采购。但是你去他朋友那边发现水果不新鲜,质量也不好,这个时候你会怎么办?
对行为犯的追诉期限应从()开始计算。
(2007下项管)为解决监理活动中产生的争议,其依据是______。
Fromitsbirth,threepowerfulimageshavecolouredideasofwhattheUnitedStateswasandwhatitstoodfor.Onewas"acityo
最新回复
(
0
)