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
37
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?
Other animals would be slowed by turbulent water, while dolphin can race through at a high speed.
选项
答案
O
解析
信息明示题。题干:其他动物受乱流影响会降低速度,但是海豚却能快速穿越水流。题干关键词是slowed by turbulent water和dolphin can race through at a high speed。O段提到Where other animals would be slowed by turbulent water at rapid speeds,the dolphin can race through the water at record breaking speeds.与题干吻合,故选O。
转载请注明原文地址:https://kaotiyun.com/show/2ra7777K
0
大学英语四级
相关试题推荐
Politicsisanemotionalbusiness.Still,manypeoplefoundthemselvesunusuallymovedbythehistoricpresidentialinauguration
VideoconferencingisnothingmorethanatelevisionsetorPCmonitorwithacamera.Throughthevideoconferencing,notonlyyo
A、Leakyroof.B、Thinwalls.C、Parkingplaces.D、Noisymusic.C细节题。女士共抱怨了两件事:Jimmy晚上播放音乐声音太大;占据了两个停车位。第二件讲的是占据停车住这件事,故选C。
A、Classmates.B、Colleagues.C、Teacherandstudent.D、Customers.C推理题。根据男士主修商业,又向女士询问这所学院里是否设有适合学习商业的学生的ESP,由此可知对话场景最有可能是学生申请海外学校
A、French.B、Italian.C、Ranch.D、Germany.C侍者说,点炸鸡排送一份沙拉,并问女士用什么样的沙拉调料。女士从侍者给出的四种调料中选了Ranch,故C正确。
A、Expectation.B、Complaint.C、Enjoyment.D、Indifference.B推断题。对话一开始男士就强调圣诞节让他觉得心力交瘁(getstressedout),因此A项和C项肯定不对。接下来男士便提到他妻子会为圣
A、Seeadoctortogetsomehelp.B、Readbooksabouttheharmofsmoking.C、Improvehisself-controllingabilities.D、Receivemen
Foryears,highschoolstudentshavereceivedidenticaltextbooksastheirclassmates.Evenasstudentshavedifferentlearning
ThingsYouCan’tSayinCanadaA)Attackingoursacredcows(thingsorpeoplethatcannotbecriticized)mayturnyouintoone
Ifthesalinity(含盐量)ofoceanwatersisanalyzed,itisfoundtovaryonlyslightlyfromplacetoplace.Nevertheless,someof
随机试题
Readthefollowingdialogueandtrytofillupthegapswithproperwords,phrases,orsentences.SalesAssoc:Hi,areyoub
血性CSF离心后,取上清液作隐血试验呈阴性,最可能是
A.伸舌吞咽B.口呼吸C.偏侧咀嚼D.咬下唇习惯E.咬上唇习惯
男性,48岁,2年前曾患乙型肝炎,近3个月血清丙氨酸氨基转移酶(ALT)反复波动100U/L左右。因发热3天伴右上腹隐痛入院,体温38.5℃。血白细胞计数11.2×109/L、中性80%,ALT1190U/L。体检:皮肤、巩膜无黄染,颈部数个蜘蛛痣,肝
背景资料A机电工程公司总承包了一新建机械厂的通风与空调工程,总工期为6个月。主、辅材料均由A机电工程公司供应。其中分部分项工程量清单计价合计为536万元;措施项目清单计价合计60万元;其他项目清单计价合计15万元。取费费率为:规费费率4.85%;
三位股评专家正在对三家上市公司明天的股价走势进行预测。甲说:“公司一的股份会有一些上升,但不能期望过高。”乙说:“公司二的股价可能下跌,除非公司一的股份上升超过5%。”丙说:“如果公司二的股价上升,公司三的股份也会上升。”股评专家果然厉害,一天后的事实表
数列极限=______________.
在结构化布线系统中的6个子系统中,(14)是整个布线系统的主干线路。
ChecklistforStartingYourOwnBusinessAreyouthinkingofstartingyourownbusiness?Beforeyoucomeupwithanameandr
Aswehaveseen,thereisnothingaboutlanguageassuchthatmakeslinguisticidentitycoextensivewithnationalidentity."If
最新回复
(
0
)