大学六级-1031及答案解析.doc

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1、大学六级-1031 及答案解析(总分:712.00,做题时间:90 分钟)一、Part Writing(总题数:1,分数:106.00)1.一些学生认为运动要以兴趣为中心2. 另一些学生认为运动要以健康为中心3. 你的看法Interest-oriented Or Health-oriented Sports(分数:106.00)_二、Part Reading Compr(总题数:1,分数:70.00)Cable TelevisionIn the 1940s, there were four networks in the United States. Because of the freque

2、ncies allotted to television, the signals could only be received in a “line of sight“ from the transmitting antenna. People living in remote areas couldnt see the programs that were already becoming an important part of U. S. culture.In 1948, people living in remote valleys in Pennsylvania solved th

3、eir reception problems by putting antennas on hills and running cables to their houses. These days, the same technology once used by remote villages and select cities allows viewers all over the country to access a wide variety of programs and channels that meet their individual needs and desires. B

4、y the early 1990s, cable television had reached nearly half the homes in the United States.Today, U. S. cable systems deliver hundreds of channels to some 60 million homes, while also providing a growing number of people with high-speed Internet access. Some cable systems even let you make telephone

5、 calls and receive new programming technologies!The earliest cable systems were, in effect, strategically placed antennas with very long cables connecting them to subscribers television sets. Because the signal from the antenna became Weaker as it traveled through the length of cable, cable provider

6、s had to insert amplifiers at regular intervals to boost the strength of the signal and make it acceptable for viewing.“In a cable system, the signal might have gone through 30 or 40 amplifiers before reaching your house, one every 1,000 feet or so,“ Wall says, “With each amplifier, you would get no

7、ise and distortion. Plus, if one of the amplifiers failed, you lost the picture. Cable got a reputation for not having the best quality picture and for not being reliable.“ In the late 1970s, cable television would find a solution to the amplifier problem. By then, they had also developed technology

8、 that allowed them to add more programming to cable service.In the early 1950s, cable systems began experimenting with ways to use microwave transmitting and receiving towers to capture the signals from distant stations. In some cases, this made television available to people who lived outside the r

9、ange of standard broadcasts. In other cases, especially in the northeastern United States, it meant that cable customers might have access to several broadcast stations of the same network. For the first time, cable was used to enrich television viewing, not just make ordinary viewing possible.The a

10、ddition of community antenna television stations and the spread of cable systems ultimately led manufacturers to add a switch to most new television sets. People could set their televisions to tune to channels, or they could set them for the plan used by most cable systems.In both tuning systems, ea

11、ch television station was given a 6-megahertz (MHz) slice of the radio spectrum. The FCC (Federal Communications Commission) had originally devoted parts of the very high frequency (VHF) spectrum to 12 television channels. The channels werent put into a single block of frequencies, but were instead

12、broken into two groups to avoid interfering with existing services.Later, when the growing popularity of television necessitated additional channels, the FCC allocated frequencies in the ultra-high frequency (UHF) portion of the spectrum. They established channels 14 to 69 using a block of frequenci

13、es between 470 MHz and 812 MHz.Because they used cable instead of antennas, cable television systems didnt have to worry about existing services. Engineers could use the mid-band, those frequencies passed over by broadcast TV due to other signals, for channels 14-22. Channels 1 through 6 are at lowe

14、r frequencies and the rest are higher. The “CATV / Antenna“ switch tells the televisions tuner whether to tune around the mid-band or to tune straight through it.While were on the subject of tuning, its worth considering why CATV systems dont use the same frequencies for stations broadcasting on cha

15、nnels 1 to 6 that those stations use to broadcast over the airwaves. Cable equipment is designed to shield the signals carded on the cable from outside interference, and televisions are designed to accept signals only from the point of connection to the cable or antenna; but interference can still e

16、nter the system, especially at connectors. When the interference comes from the same channel thats carded on the cable, there is a problem because of the difference in broadcast speed between the two signals.Radio signals travel through the air at a speed very close to the speed of light. In a coaxi

17、al (同轴的) cable that brings CATV signals to your house, radio signals travel at about two-thirds the speed of light. When the broadcast and cable signals get to the television tuner a fraction of a second apart, you see a double image called “ghosting“.In 1972, a cable system in Wilkes-Barre, PA, beg

18、an offering the first “pay-per-view“ channel. The customers would pay to watch individual movies or sporting events. They called the new service Home Box Office, or HBO. It continued as a regional service until 1975, when HBO began transmitting a signal to a in geosynchronous (与地球的相对位置不变的) orbit and

19、 then down to cable systems. These early satellites could receive and retransmit up to 24 channels. The cable systems receiving the signals used dish antennas 10 meters in diameter, with a separate dish for each channel!As the number of program options grew, the bandwidth of cable systems also incre

20、ased. Early systems operated at 200 MHz, allowing 33 channels. As technology progressed, the bandwidth increased to 300,400,500 and now 550 MHz, with the number of channels increasing to 91. Two additional advances in technology - fiber optics and analog-to-digital conversion - improved features and

21、 broadcast quality while continuing to increase the number of channels available.In 1976, a new sort of cable system debuted. This system used fiber-optic cable for the trunk cables that carry signals from the CATV head-end to neighborhoods. The head-end is where the cable system receives programmin

22、g from various sources, assigns the programming to channels and retransmits it onto cables. By the late 1970s, fiber optics had progressed considerably and so were a cost. Effective means of carrying CATV signals over long distances. The great advantage of fiber-optic cable is that it doesnt suffer

23、the same signal losses as coaxial cable, which eliminated the need for so many amplifiers. Another benefit that came from the move to fiber-optic cable was greater customization. Since a single fiber-optic cable might serve 500 households, it became possible to target individual neighborhoods for me

24、ssages and services.In 1989, General Instruments demonstrated that it was possible to convert an analog cable signal to digital and transmit it in a standard 6-MHz television channel. Using MPEG compression, CATV systems installed today can transmit up to 10 channels of video in the 6-MHz bandwidth

25、of a single analog channel. When combined with a 550-MHz overall bandwidth, this allows the possibility of nearly 1,000 channels of video on a system. In addition, digital technology allows for error correction to ensure the quality of the received signal, also changed the quality of one of cable te

26、levisions most visible features: the scrambled channel.The first system to “scramble“ a channel on a cable system was demonstrated in 1971. In the first scrambling system, one of the signals used to synchronize the television picture was removed when the signal was transmitted, then reinserted by a

27、small device at the customers home. Later scrambling systems inserted a signal slightly offset from the channels frequency to interfere with the picture, then filtered the interfering signal out of the mix at the customers television. In both cases, the scrambled channel could generally be seen as a

28、 jagged, disarranged set of video images.In a digital system, the signal isnt scrambled, but encrypted (加密的). The signal must be decoded with the proper key. Without the key, the digital-to-analog converter cant turn the stream of bits into anything usable by the televisions tuner. When a “non-signa

29、l“ is received, the cable system substitutes an advertisement or the familiar blue screen.(分数:70.00)(1).In 1948, people living in remote areas could see TV programs by _ in the United States.(分数:7.00)A.a “line of sight“B.transmitting antennaC.frequencies allotted to televisionD.putting antennas on h

30、ills and running cables to houses(2).In the United States, cable television had come to nearly fifty percent of the homes by _.(分数:7.00)A.1948B.1940sC.1970sD.1990s(3).How did cable providers solve the problem of the earliest cable systems?(分数:7.00)A.They strategically placed antennas with very long

31、cables connecting to subscribers television sets.B.They made the signal from the antenna travel through the length of cable.C.They inserted amplifiers at regular intervals.D.They increased the length of cable.(4).Cable television had developed technology that allowed them to add more programming to

32、cable service in _.(分数:7.00)A.In the early 1990sB.In the late 1970sC.In the early 1950sD.In the early 1940s(5).Whats the purpose of the manufacturers adding a switch to most new television sets?(分数:7.00)A.To make more money.B.To spread the cable system.C.To make ordinary viewing possible.D.To adapt

33、to the new development of the cable system.(6).What do we know about the “ghosting“ from the passage?(分数:7.00)A.It is a double image of TV.B.It refers to the speed of light.C.It was eventually solved by engineers.D.It refers to the speed of the radio signals.(7).As the bandwidth increased to 550 MHz

34、, the number of TV channels increased by _compared with the early cable systems.(分数:7.00)A.24B.33C.58D.91(8).Cable systems began tying to use _ to capture the signals from distant stations in the early 1950s.(分数:7.00)填空项 1:_(9).In tuning system, the Federal Communications Commission had distributed

35、parts of _ spectrum to 12 television channels which were broken into two groups to avoid interference with existing services at the beginning.(分数:7.00)填空项 1:_(10).In a digital cable system, if there is no key to decode the signal, then, we will only see _.(分数:7.00)填空项 1:_三、Part Listening Com(总题数:0,分

36、数:0.00)四、Section A(总题数:3,分数:105.00)Questions 11 to 18 are based on the conversation you have just heard.(分数:56.00)A.Robert survived the plane crash.B.All the passengers were killed in the plane crash.C.Robert was killed in the air crash.D.Robert is a wonder-working person.A.Because she feels very ho

37、t in the room.B.Because she wants to avoid meeting people.C.Because she wants to smoke a cigarette outside.D.Because she doesnt like the smell of smoke inside.A.He thinks David is not reliable.B.Hes willing to trust David.C.He has told his doubts to David.D.He thinks David will benefit from this exp

38、erience.A.The man can have his pants at the end of the day.B.Cleaning the pants will take longer than usual.C.She doesnt think the stain can be removed.D.The man should go to a different location.A.The man should start running daily.B.She also prefers to exercise in the afternoon.C.Its important to

39、warm up before exercising.D.The man should continue his exercise program.A.The professor postponed the exam and will inform everyone later.B.The professor phoned him about the postponing of the exam.C.The professor canceled the exam.D.The professor put off the exam.A.The woman had been planning for

40、the conference.B.The woman called the man but the line was busy:C.The woman didnt come back until midnight.D.The woman had guests all evening.A.They should wait patiently.B.They should ask that man to leave.C.They should serve that man immediately.D.That man is old enough to order things he likes.Qu

41、estions 19 to 22 are based on the conversation you have just heard.(分数:28.00)A.She loved it.B.She disagreed with too much of it to enjoy.C.She thought it was just so so.D.She liked the class but disagreed with the Professor.A.Early America was undemocratic.B.There has never been democracy in America

42、,C.Early leaders of America had no desire for democracy.D.Democracy took time to develop in America,A.The basic foundations of democracy were created over 200 years ago.B.Early leaders loved democracy but didnt not hated it.C.America is no different now than 200 years ago.D.The meaning of democracy

43、has changed over time.A.She is afraid he may discover her ignorance.B.She is afraid it may affect her grade.C.She is not completely sure of her own opinion.D.She is too busy and has no time to waste.Questions 23 to 25 are based on the conversation you have just heard.(分数:21.00)A.To prove womens dili

44、gence.B.To seek gender equality on campus.C.To improve transportation and accommodation.D.To put pressure on male students.A.To give an example of inequality.B.To show the positive side of equality.C.To show an example of the role model.D.To emphasize that women are superior to men.A.He was surely u

45、nder huge pressure.B.The cafeteria was not one of his greatest achievements.C.He did almost nothing significant.D.He was the greatest leader of the students union.五、Section B(总题数:3,分数:70.00)Passage OneQuestions 26 to 28 are based on the passage you have just heard.(分数:21.00)A.How historical events a

46、ffected an art movement.B.How artists can influence economic conditions.C.Why a certain art movement failed to become popular.D.How valuable paintings were lost during wartime.A.People working in a large factory.B.People walking on crowded city streets.C.An everyday activity in a small town.D.A well

47、-known historical event.A.The populations of small towns increased rapidly.B.Art critics in cites began to take notice of regionalism.C.Some regionalist painters began a new art movement.D.Society became more internationally focused.Passage TwoQuestions 29 to 31 are based on the passage you have jus

48、t heard.(分数:21.00)A.It is the first oldest bridge in New York.B.It is the first suspension bridge built in the USA.C.It is the first suspended railway bridge in the USA.D.It is the first suspension bridge between Manhattan Island and Brooklyn.A.John Augustus Roebling fell ill.B.Misfortune fell on th

49、e chief engineer.C.The chief engineer was in short of money.D.Washington Roebfing met with an accident.A.Direct the building work on the bridge.B.Lead the builders of the bridge in a hospital.C.Direct the construction of the bridge by radio.D.Give his directions to the workers from a flat nearby.Passage ThreeQuestions 32 to 35 are based on the passage you have just heard.(分数:28.00)A.The

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