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
33
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 tail whips, because the energy on each side of the body is different.
选项
答案
H
解析
信息明示题。题干:尾巴强烈移动是因为身体两侧的能量是不同的。题干关键词是tail whips和energy on each side of the body is different。H段提到As energy is alternately stored and released on both sides of the animal’s body,the tail whips strongly back and forth.与题干吻合,故选H。
转载请注明原文地址:https://jikaoti.com/ti/OVUFFFFM
0
大学英语四级
相关试题推荐
Britainisnotjustonecountryandonepeople:evenifsomeofitsinhabitantsthinkso.Britainis,infact,anationwhichca
A、Thelifecycleoftrees.B、Thenumberoftrees.C、Theintensityofsolarburning.D、Thequalityofair.C细节题。短文中提到,太阳燃烧得越热烈,太阳风
A、Itispositive.B、Itisnegative.C、Ithastwosides.D、Thefriendshiphasnothingtodowiththeworkplace.C细节题。根据对话,男士表示工作场
A、Crowdedhouses.B、Pollutedwaterfromfactories.C、Highcrimerate.D、Continualnoise.D文中列举了城市生活的四大不利之处:hous-ing,pollution,hi
A、Shewasdishonestinbusinessdealings.B、Shefrequentlyill-treatedheremployees.C、Sheabusedanimalsincludingherpetdog
Foryears,highschoolstudentshavereceivedidenticaltextbooksastheirclassmates.Evenasstudentshavedifferentlearning
Divorcedoesn’tnecessarilymakeadultshappy.Buttoughingitoutinanunhappymarriageuntilitturnsaroundjustmightdo,a
ThingsYouCan’tSayinCanadaA)Attackingoursacredcows(thingsorpeoplethatcannotbecriticized)mayturnyouintoone
Divorcedoesn’tnecessarilymakeadultshappy.Buttoughingitoutinanunhappymarriageuntilitturnsaroundjustmightdo,a
A、Birdswillnothaveenoughfoodtosurvivethewinter.B、Therearetoomanybirdslivinginthesameplace.C、Birdsreivingon
随机试题
男性,32岁。半年来心悸、多汗及消瘦,昨起心悸加重,心电图如下。患者除了病因治疗以外,针对心律失常应予以哪种药物治疗为最佳选择
解除尿潴留的措施中哪项是错误的
有机磷中毒患者迟发性神经损害的主要临床表现是
【2011年第3题】题21~25:某座建筑物由一台1000kVA变压器采用TN—C—S系统供电,线路材质、长度和截面如下图所示,图中小间的移动式设备由末端配电箱供电,回路首端装有单相In=20A断路器,建筑物作总等电位联结,已知截面为50mm2、6mm2、
未结清的债权债务原始凭证和涉及其他未了事项的原始凭证,应由档案部门保管到未了事项完结后才能销毁。()
甲公司因欠付货款被乙公司申请法院强制执行,法院决定对甲公司所持丙有限责任公司的股权予以强制执行。丁公司(非丙公司的股东)表示愿意受让该项股权。根据公司法律制度的规定,下列表述中,正确的有()。
1774年,拉瓦锡用精确的定量实验研究了氧化汞的分解和合成反应中各物质质量之间的变化关系。他将45.0份质量的氧化汞加热分解,恰好得到了41.5份质量的汞和3.5份质量的氧气,于是他认为化学反应中反应物的质量总和与生成物的质量总和是相等的,而且反应前后各元
皮亚杰根据认知发展,把游戏划分为()。
Cocaine’seffectsonthehearthave______goneunnoticed,becausepatientsoftenlieaboutheiruseofdrug.
空中客车A380是法国空中客车公司的最新巨型客机,也是全球载客量最大的客机。A380为双层四引擎客机,采用最高密度座位安排时可承载850名乘客,在典型三舱等配置(头等—商务—经济舱)下也可承载555名乘客。A380于2005年4月27日首飞成功,并于同年的
最新回复
(
0
)