大学四级-214及答案解析.doc

《大学四级-214及答案解析.doc》由会员分享，可在线阅读，更多相关《大学四级-214及答案解析.doc（33页珍藏版）》请在麦多课文档分享上搜索。

1、大学四级-214 及答案解析(总分：693.00，做题时间：90 分钟)一、BPart Writing(总题数：1，分数：106.00)1.中国城乡之间的差距似乎有增大的趋势 2. 导致这种现象的原因 3. 怎样才能缩小城乡之间的差距 BBridging the Gap between the Urban and Rural Areas/B _（分数：106.00）_二、BPart Reading (总题数：1，分数：70.00)BRadio and Television/BRadio and television were major agents of social change in t

2、he 20th century. Radio was once the center for family entertainment and news and television enhanced this revolution by adding sight to sound. Both opened the windows to other lives, to remote areas of the world, and to history in the making. News coverage changed from early and late editions of new

3、spapers to broadcast coverage from the scene. Play-by-play sports broadcasts and live concerts enhanced entertainment coverage. For many, the only cultural performances or sports events they would ever hear or see would come from the speakers or the screens in their living rooms. Each has engaged mi

4、llions of people in the major historical events that have shaped the world.If people could look at the sky and see how it is organized into frequency“ bands used for different purposes, they would be amazed. Radio waves crisscross (十字形) the atmosphere at the speed of tight, delivering incredible amo

5、unts of informationnavigational data, radio signals, television picturesusing devices for transmission and reception designed, built, and refined by a century of engineers.Key figures in the late 1800s included Nikola Tesla, who developed the Tesla coil, and James Clerk Maxwell and Heinrich Hertz, w

6、ho proved mathematically the possibility of transmitting electromagnetic signals between widely separated points. It was Guglielmo Marconi who was most responsible for taking the theories of radio waves out of the laboratory and applying them to practical devices. His “wireless“ telegraph demonstrat

7、ed its great potential for worldwide communication in 1901 by sending a signalthe letter “s“in Morse code a distance of 2 000 miles across the Atlantic Ocean. Radio technology was just around the comer.Immediate engineering challenges addressed the means of transmitting and receiving coded messages,

8、 and developing a device that could convert a high-frequency oscillating (振荡的) signal into an electric current capable of registering as sound. The first significant development was “the Edison effect“, the discovery that the carbon filament (灯丝) in the electric light bulb could send out a stream of

9、 electrons to a nearby test electrode if it had a positive charge. In 1904, Sir John Ambrose Fleming of Britain took this one step further by developing the diode (二极管) which allowed electric current to be detected by a telephone receiver. Two years later, American Lee De Forest developed the triode

10、 (三极管), introducing a third electrode (the grid) between the filament and the plate. It could amplify a signal to make live voice broadcasting possible, and was quickly added to Marconis wireless telegraph to produce the radio.Radio development was prevented by restrictions placed on airwaves during

11、 World War I. Technical limitations were also a problem. Few people had receivers, and those that did had to wear headphones. Radio was seen by many as a hobby for telegraphy fans. It would take a great deal of engineering before the radio would become the unifying symbol of family entertainment and

12、 the medium for news that was its destiny.In the mid-1920s, technical developments expanded transmission distances, radio stations were built across the country, and the performance and appearance of the radio were improved. With tuning circuits, capacitors, microphones, oscillators, and loudspeaker

13、s, the industry blossomed in just a decade. By the mid-1930s almost every American household had a radio. The appearance of the transistor in the 1950s completely transformed its size, style, and portability.Both television and radar were logical byproducts of the radio. Almost 50 years before telev

14、ision became a reality, its fundamental principles had been independently developed in Europe, Russia, and the United States. John Baird in England and Charles Jenkins in the United States worked independently to combine modulated light and a scanning wheel to reconstruct a scene. In 1925, Baird suc

15、ceeded in transmitting a recognizable image.Philo T. Farnsworth, a 21-year-old inventor from Utah, patented a scanning ray tube, and Vladimir Zworykin of RCA devised a superior television camera in 1930. Regularly scheduled broadcasts started shortly thereafter, and by the early 1940s there were 23

16、television stations in operation throughout the United States.Shortly after World War , televisions began to appear on the market. The first pictures were faded and flickering, but more than a million sets were sold before the end of the decade. An average set cost $500 at a time when the average sa

17、lary was less than $3 000 a year. In 1950 engineers perfected the process of production and prices dropped to $200 per set. Within 10 years 45 million units were sold.A study of how human vision works enabled engineers to develop television technology. Images are retained in a viewers eye for only a

18、 fraction of a second after they strike it. By displaying images piece by piece at sufficient speed, the illusion of a complete picture can be created. By changing the image on the screen 25 to 30 times per second, movement can be realistically represented. Early scanning wheels slowly built a pictu

19、re line by line. In contrast, each image on a modern color television screen is comprised of more than 100 000 pixels (像素), arranged in several hundred lines. The image displayed changes every few hundredths of a second. For a 15-minute newscast, the television must accurately process more than 1 bi

20、llion units of information. Technical innovations that made this possible included a screen coated with millions of tiny dots of fluorescent compounds that emit light when struck by high: speed electrons.Today this technology is in transition again, moving away from conventional television waves and

21、 on to separate digital signals. This holds the potential for making television interactiveallowing a viewer to play a game or order action replays. Cathode ray tubes with power-hungry electron guns are giving way to liquid crystal display (LCD) panels. Movie-style wide screens and flat screens are

22、readily available. Digital signals enable High Definition Television (HDTV) to have almost doubled the usual number of pixels, giving a much sharper picture. The appearance of cable television and advances in fiber-optic technology will also help lift the present bandwidth (带宽) restrictions and incr

23、ease image quality.（分数：70.00）(1).The major difference between radio and television is _ .（分数：7.00）A.whether they can broadcast cultural performancesB.whether they may attract millions of people in the great historical eventsC.whether they open the windows to remote areas of the worldD.whether they m

24、ay offer sights to the people(2).Which scientist first applied the theories of radio waves to practical devices?（分数：7.00）A.Nikola Tesla.B.Guglielmo Marconi.C.Clerk Maxwell.D.Heinrich Hertz.(3).What discovery made live voice broadcasting become a reality?（分数：7.00）A.Carbon filament.B.Diode.C.Triode.D.

25、Wireless telegraph.(4).During World War I, radio _ .（分数：7.00）A.was very popular among the publicB.was the symbol of family entertainmentC.had developed to a high levelD.was facing some technical problems(5).When did radio come into the common American household in a large scale?（分数：7.00）A.In the Wor

26、ld War I.B.In the middle of 1920s.C.By the middle of 1930s.D.In the 1950s.(6).After radio had developed to a very high level, what appeared as a necessary result?（分数：7.00）A.Television and radar.B.Modulated light and a scanning wheel.C.Superior television camera.D.Microphones and loudspeakers.(7).How

27、 many sets of televisions were sold in the decade of 1950?（分数：7.00）A.More than a million.B.45 million.C.50 million.D.100 million.(8).Movement can be indeed showed only if the images on the screen are changed at the frequency of _ .（分数：7.00）填空项 1:_(9).Television will probably become interactive if th

28、e television waves are changed into _ .（分数：7.00）填空项 1:_(10).Present bandwidth restrictions may be raised and image quality may be increased with the help of _ .（分数：7.00）填空项 1:_三、BPart Listenin(总题数：6，分数：175.00)Questions 11 to 18 are based on the conversation you have just heard. （分数：56.00）A.Shed rath

29、er take a break later.B.She likes the suggestion.C.She never drinks soda.D.She doesnt think he is serious.A.Johns phone wasnt working.B.John wasnt at home when she called.C.The woman didnt get the right phone number of Johns.D.John was too busy to come.A.$36.B.$40.C.$100.D.$150.A.Drop out of the pla

30、y.B.Switch parts with another actor.C.Be patient about learning his part.D.Have his lines memorized by tomorrow.A.By going on a diet.B.By reading more books.C.By riding a bike.D.By eating more fruits.A.Tea is better than coffee.B.The man should switch to tea.C.The man should drink coffee.D.The man s

31、houldnt drink tea either.A.In a doctors office.B.In an operating room.C.In a professors office.D.In a gymnasium.A.He thinks the woman is wasting her time.B.He thinks the woman should make full use of her time.C.He is eager to know the womans answer.D.He thinks there is no need for the woman to hurry

32、.Questions 19 to 22 are based on the conversation you have just heard. （分数：28.00）A.There arent enough cabinets.B.There is too much noise.C.Office supplies are taking up space.D.Some teaching assistants dont have desks.A.To chat with Jack socially.B.To get help in the course.C.To hand in their assign

33、ments.D.To practice giving interviews.A.Give Jack a different office.B.Complain to the department head.C.Move the supplies to the storage room.D.Try to get a room to use for meetings.A.Theyd have to get permission.B.Jack wouldnt like it.C.He thinks it might work.D.The other assistants should be cons

34、ulted.Questions 23 to 25 are based on the conversation you have just heard. （分数：21.00）A.He gets ill at the same time every year.B.He doesnt get enough exercise.C.He often has difficulty sleeping.D.Hes sick with influenza throughout the winter.A.To find out if he has the flu.B.To find out how to main

35、tain a nutritious diet.C.To find out how to prevent illness.D.To find out the results of a blood test.A.Hes unwilling to be immunized.B.He is exposed to viruses in the crowdC.He forgets to take his medicine.D.He doesnt dress warmly enough.BSection B/BBPassage 1/BBQuestions 26 to 29 are based on the

36、passage you have just heard. /B（分数：28.00）A.What is romantic love?B.What causes love?C.How do we react to love?D.Why are we attracted to love?A.We love to talk to ourselves about what we care about.B.We are influenced by what we actually feel.C.We are subjective about our own feelings.D.We are subjec

37、t to our desires and frustrations.A.It often requires long distance between the lovers.B.It may last for a long time.C.It is difficult to get.D.It helps people achieve success in careers.A.It is more lasting and satisfying than romantic love.B.It is based on open communications with each other.C.It

38、is more difficult to achieve than romantic love.D.It happens more frequently than romantic love.BPassage 2/BBQuestions 30 to 32 are based on the passage you have just heard. /B（分数：21.00）A.He wants to make millions of dollars from doing so,B.He believes the pills can help save patients there.C.The th

39、rown away pills were piling up in American hospitals.D.He has established his own clinics on the African continent.A.He was a nurse working in a hospital.B.He was a medical doctor in a hospital.C.He was a journalist for a newspaper.D.He was a travel agent in San Francisco.A.He has stolen the thrown

40、away pills.B.He practiced medicine without a license in Africa.C.Thrown away pills can not he given away.D.He has not reported his doing to the court.BPassage 3/BBQuestions 33 to 35 are based on the passage you have just heard. /B（分数：21.00）A.The loss of natural habitat for many species.B.Less space

41、for building new homes.C.Less carbon dioxide and oxygen.D.Reduced supply of paper and wood.A.Continued rainfalls.B.The increase of carbon dioxide.C.The disappearance of grasslands.D.Less land for cows and sheep.A.Reusing and recycling paper.B.Prohibiting tree cutting.C.Planting more trees than they

42、cut down.D.Reducing emissions of carbon dioxide.四、BSection C/B(总题数：1，分数：77.00)Education is compulsory and free for every child in the United States. Most children start school by the age of six. They attend eight years ofU (36) /Uschools and four years of high school orU (37) /Uschool. The money for

43、 free public schools comes from taxes, and each state isU (38) /Ufor its own educational system. State legislatures set the educational requirements but leave theU (39) /Uof the schools in the hands of theU (40) /Ucommunities. Most states require their children to go to school until a certain age. T

44、his ageU (41) /Ufrom 10 to 18 years according to the laws of theU (42) /Ustates. The Federal governmentU (43) /Ufunds to the states for additional school and school services.U (44) /U. One may go to a twoyear college, a four year college, a university, or a specialized professional schooleither publ

45、ic or private. Most colleges admit students on the basis of their high school records. U(45) /U. Many students receive scholarships from the schools, governments, or private foundations and organizations. U(46) /U. Only 2 percent of the population of the country cannot read and write.（分数：77.00）(1).（

46、分数：7.00）填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_填空项 1:_五、BPart Reading (总题数：3，分数：170.00)In colleges almost half a million students have to take the course of introductory Calculus(微积分)in any academic year, and the number is growing. A largeU (47) /Uhave no choice. Calcu

47、lus is aU (48) /Uthat must be overcome on the way to a professional career in medicine or engineering. Even disciplines like history now sometimesU (49) /Usome college mathematics.But for many people who in the last few years have passed through such a course, the word “Calculus“ brings back painful memories. In many universities about half of the students who take the course fail it. AU (50) /Ularge number must take the course several times to get through. At the same time, engineering and physical sciences professorsU (51) /Uthat