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70天攻克考研英语阅读 DAY30

2006-7-28 01:04  

  Increasing reading speed

  Directions:Do the word recognition drills below.Note the words on the left;then underline it every time it appears in the same form to the right.No regression,no vocalization.Try to finish in 15 seconds or less.

  Starting Time:

  1. actionactive actual actress acting action

  2. struggle       structure stroll strong struggle strange

  3. dramatic       drama dramatics dramatist dramatic dramatize

  4. escape               escapee escapism escort escape escapade

  5. rocket               rocker rocketry robbery rocket market

  6. contain              contend content container contain contest

  7. energy               energize energetic energetics energy engage

  8. radial               radiant radiate radial radiator radiocast

  9. stretch              stress stretcher straight stretch strength

  10. effect              affect effective effectual efferent effect

  Finishing Time: Total Reading Time.

  Errors: Check each line carefully for mistakes.

  CAUTION:Animals on the MoveIt looked like a scene from "Jaws" but without the dramatic music. A huge shark was slowly swimming through the water,its tail swinging back and forth like the pendulum of a clock.

  Suddenly sensitive nerve endings 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 SurviveIn pursuing its prey,the shark demonstrated in a dramatic way the important role of movement,or locomotion,in animals.

  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.

  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 Marineland 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 KeyThe 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.

  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.

  As energy is alternately stored and released on both sides of the animal's body,the tail whips strongly back and forth. This whiplike action propels the animal through the water like a living bullet.

  Source of EnergyWhat 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.

  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.

  The pressure inside the animal may increase by 10 times. This pressure change greatly stretches the fibers,enabling much energy to be stored.

  This energy is then transferred to the tail,and the shark is off. The rest of the story is predictable.

  Dolphin Has Speed RecordAnother fast marine 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.

  In a dolphin the skin is so flexible that it bends and yields to the waviness of the water.

  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 EfficientNot all animals move as efficiently as sharks and dolphins. Perhaps the greatest loser in locomotion efficiency is the slug. The slug,which looks like a snail without a shell,lays down a slimy trail over which it crawls. It uses so much energy producing the slimy mucus and crawling over it that a mouse traveling the same distance uses only one twelfth as much energy.

  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?

  ——from Current Science,Dec. 17,1980

  Time: 989 words=wpm

  Minutes

  EXERCISESⅠ。READING COMPREHENSION

  Select the answer which is most accurate according to the information given in the passage.

  1. How does a shark find its prey?

  A. By hearing the sound produced by a prey.

  B. By detecting the odor given off by a prey.

  C. By feeling the vibrations of a struggling prey.

  D. Both A and B.

  2. Automobiles,rockets,and submarines (paragraph 5)are all examples given to  .

  A. support the idea that human inventions enable us to travel in almost any kind of environment

  B. demonstrate how intelligent humans are

  C. illustrate how fast humans can travel in different environments

  D. show how successful human evolution has been

  3. As it is used in paragraph 5,the phrase,"zero in on something" means .

  A. swallow somethingB. catch something

  C. tear something into pieces             D. swim directly at something

  4. The  of the shark contributes to its swift locomotion.

  A. tail  B. skin

  C. nerve endings in the skin                    D. snout

  5. According to the passage, collagen fibers can be compared to the string of a bow for both of them .

  A. can be pulled tight when needed

  B. contain fibers that cross one another in different directions

  C. store energy when stretched

  D. are elastic

  6. The greatest stretching of the collagen fibers occurs when a shark .

  A. jerks its headB. swings its tail slowly

  C. tears huge chunks of flesh from its preyD. bends its body

  7. The area just under the sharks collagen fibers is similar to a belted radial tire because          .

  A. it is also inflated by pressureB. it is also filled with air

  C. it is also flexible D. none of the above

  8. A laminar flow is formed .

  A. when a fish races through the water at an incredible speed

  B. when a fish swims slowly through the water

  C. when a fish swims against the current

  D. even when a shark or dolphin knifes through the water at a fantastic speed

  9. Consuming the equal amount of energy as a slug does,a mouse can travel  as long as a slug.

  A. 14 timesB. 13 timesC. 12 timesD. 11 times

  10. Which of the following statements is true according to the passage?

  A. The dolphin and the shark are among the largest fishes in the ocean.

  B. Dolphins are the fastest sea fish.

  C. Turbulence occurs when an object flows through the water.

  D. Unlike the shark,the dolphin is not a fish.

  Ⅱ。 CONTEXTUAL REFERENCE

  Guess the meaning of the following words in italics using reading techniques.

  1. Reptiles are strange and beautiful animals. Reptiles have bodies that are covered with small scales. Lizards and snakes are reptiles.

  2. Some snakes are very poisonous. They have fangs which are like sharp, hollow teeth. When these snakes bite, the fangs fill with poison which can kill small animals and people, too.

  3. Hibernation is a state of inactivity in which some animals pass the winter.

  4. Some animals do not eat during the winter and only come out in spring;we call them hibernating animals.

  5. For example,Lamarck thought that giraffes developed long necks because they had to stretch to reach the leaves of tall trees for food.

  6. The number of tigers in the world is dwindling rapidly and the animal may one day become extinct.

  7. There is a fish with an antifreeze substance in its blood that keeps it from freezing at the South Pole.

  8. Dolphins make many kinds of whistling and grunting noises. These noises are a kind of dolphin talk.

  Ⅲ。 CLOZE

  Complete the following passage by filling in the blanks with appropriate words.

  Animal Athletes

  The camel is a slow moving creature. But what it lacks in speed it gains in stamina(耐力)。 This veritable(名副其实的) beast of burden can walk 30 miles a day carrying a load that weighs half a ton.

  The kangaroo,    1  its long, muscular hind legs, is a marvel     2     fitness. Weighing 3     200 pounds, it can thrust its heavy body     4     the air and     5     a fence nine feet high. While airborne, this leaping marsupial (有袋动物) uses     6      thick tail     7     both a counterbalance and a rudder.

  Never underestimate the     8     of an insect. The tiny ant can raise burden 50     9     its weight. And the strong bee,    10   tethered (拴) to a small load   11   wheels, is able to haul up to 300 times   12   own weight.

  One of the worlds longest   13   is the flea. It can   14   13 inches - about 350 times its own   15. For a person six feet tall, this would be like   16   approximately 9000 feet, or  17     seven football fields. No one has   18    leaped even as much as 30 feet.

  A seemingly inexhaustible  19  is the Oriental rat flea(东方鼠蚤)。 It can jump 600 times an hour     20     three whole days without stopping.

  By land,air or sea,birds are masters of locomotion. The ostrich outruns any animal on two legs,carrying its 300pound body at 30 miles an hour. The flight of the Indian swift (褐雨燕)sometimes exceeds 100 mph. And the gentoo penguin (福克兰群岛企鹅),by at least one account,can swim 22 mph. At this speed,the penguin keeps pace with one of the fastest swimming marine mammals,the dolphin.

  ——from Science Digest,Dee. 1983

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