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
66
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?
During the body’s back and forth motion, much potential energy will be stored in the fibers.
选项
答案
G
解析
信息明示题。题干:当身体前后移动时,许多潜在的能量被储存在纤维中。题干关键词是body’s back and forth motion和much potential energy。G段提到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.与题干吻合,故选G。
转载请注明原文地址:https://kaotiyun.com/show/Gra7777K
0
大学英语四级
相关试题推荐
Becauseofsatellitelinkswhichnowenablebroadcastnewsorganizationstooriginateliveprogrammingfromanypartoftheglob
A、Becausefoxeskillfarmanimals.B、Becausefoxeslookjustlikefarmdogs.C、Becausefoxesareverycunning.D、Becausefoxesm
A、Tourism.B、Businessstudies.C、Informationtechnology.D、English.B细节题。男士提到他主修商务。关键词“majorin”意为“主修”。B项正确。
Acidrain,whichisaformofairpollution,currentlybecomesasubjectofgreatdebatebecauseofwidespreadenvironmentaldam
AdequatePreparationShouldBeGiventoExams1.如今不少大学生在考试前不做充分的准备2.出现这种现象的原因是…3.为了改变这种状况,我认为…
A、AnEarforMusic.B、MusicAppreciation.C、MuscleParticipationinMentalActs.D、ADefinitionoftheThinkingProcess.C预读选项可知
A、Shewasdishonestinbusinessdealings.B、Shefrequentlyill-treatedheremployees.C、Sheabusedanimalsincludingherpetdog
Infact,evenwithouthumans,theEarth’sclimatechanges.Someclimatechangeis【C1】______.But,asgreenhousegasesareadded
Divorcedoesn’tnecessarilymakeadultshappy.Buttoughingitoutinanunhappymarriageuntilitturnsaroundjustmightdo,a
Ifthesalinity(含盐量)ofoceanwatersisanalyzed,itisfoundtovaryonlyslightlyfromplacetoplace.Nevertheless,someof
随机试题
有关子宫输卵管造影的叙述,错误的是
具有一根地线时单回路线路的零序阻抗计算公式为:
下列有关“主营业务收入”账户的说法正确的是()。(2.2)
某投资者将10000元投资于票面利率10%、5年期的债券,则此项投资的终值按复利计算是()。
()也被称为“酸性测试比率”。
A公司2007年至2009年发生与金融资产有关的业务如下:(1)2007年1月1日,A公司支付2360万元购入甲公司于当日发行的5年期债券20万张,每张面值100元,票面利率7%,每年年末付息,到期一次还本,另支付相关费用6.38万元。A公司将其
情感反应技术的实施方法包括()。
1942年,盟军在太平洋战场组织了一次战役,使太平洋战场局势发生了根本性转折。这场战役是()。
各级人大代表受()监督。
计算:12-22+32-42+52-62+…-1002+1012=()
最新回复
(
0
)