1、大学英语六级模拟试卷 459及答案与解析 一、 Part I Writing (30 minutes) 1 Directions: For this part, you are allowed 30 minutes to write a short essay entitled Does Intensive Training Courses Really Help ? You should write at least 150 words following the outline given below: 1. 现如今各种考试的辅导班越来越多 2人们对此看法不一 3你的观点 Does Int
2、ensive Training Courses Really Help 二、 Part II Reading Comprehension (Skimming and Scanning) (15 minutes) Directions: In this part, you will have 15 minutes to go over the passage quickly and answer the questions attached to the passage. For questions 1-4, mark： Y (for YES) if the statement agrees w
3、ith the information given in the passage; N (for NO) if the statement contradicts the information given in the passage; NG (for NOT GIVEN) if the information is not given in the passage. 1 Part Reading Comprehension (Skimming and Scanning) Directions: In this part, you will have 15 minutes to go ove
4、r the passage quickly and answer the questions on Answer Sheet 1. For questions 1-7, choose the best answer from the four choices marked A), B), C) and D). For questions 8-10, complete the sentences with the information given in the passage. Satellite Today, you see compact satellite dishes perched
5、on rooftops all over the United States. Drive through rural areas beyond the reach of the cable companies and youll find dishes on just about every house. The major satellite television companies are bringing in more customers every day with the lure of movies, sporting events and news from around t
6、he world. The Broadcast TV Problem Conceptually, satellite television is, a lot like broadcast television. Its a wireless system for delivering television programming directly to a viewers house. Both broadcast television and satellite stations transmit programming via a radio signal. Broadcast stat
7、ions use a powerful antenna to transmit radio waves to the surrounding area. Viewers can pick up the signal with a much smaller antenna. The main limitation of broadcast television is range. The radio signals used to broadcast television shoot out from the broadcast antenna in a straight line. In or
8、der to receive these signals, you have to be in the direct “line of sight“ of the antenna. One problem is that the Earth is curved, so it eventually breaks the signals line of site. The other problem with broadcast television is that the signal is often distorted even in the viewing area. To get a p
9、erfectly clear signal like you find on cable, you have to be pretty close to the broadcast antenna without too many obstacles in the way. The Satellite TV Solution Satellite television solves the problems of range and distortion by transmitting broadcast signals from satellites orbiting the Earth. S
10、ince satellites are high in the sky, there are a lot more customers in the line of site. Satellite television systems transmit and receive radio signals using specialized antennas called satellite dishes. The television satellites are all in geosynchronous orbit, meaning that they stay in one place
11、in the sky relative to the Earth. Each satellite is launched into space at about 7,000 mph (11,000kph), reaching approximately 22,200 miles (35,700km) above the Earth. At this speed and altitude, the satellite will revolve around the planet once every 24 hoursthe same period of time it takes the Ear
12、th to make one full rotation. In other words, the satellite keeps pace with our moving planet exactly. This way, you only have to direct the dish at the satellite once, and from then on it picks up the signal without adjustment, at least when everything works right. The Overall System Early satellit
13、e TV viewers were explorers of sorts. They used their expensive dishes to discover unique programming that wasnt necessarily intended for mass audiences. The dish and receiving equipment gave viewers the tools to pick up foreign stations, live feeding between different broadcast stations, NASA activ
14、ities and a lot of other stuff transmitted using satellites. Some satellite owners still seek out this sort of programming on their own, but today, most satellite TV customers get their programming through a direct broadcast satellite (DBS) provider, such as Direct TV or the Dish Network. The provid
15、er selects programs and broadcasts them to subscribers as a set package. Basically, the providers goal is to bring dozens or even hundreds of channels to your television in a form that approximates the competition, cable TV. Unlike earlier programming, the providers broadcast is completely digital,
16、which means it has much better picture and sound quality. Early satellite television was broadcast in C-band radio radio in the 3.4-gigabertz (GHz) to 7-GHz frequency range. Digital broadcast satellite transmits programming in the Ku frequency range (12 GHz to 14 GHz ). The Programming Satellite TV
17、providers get programming from two major sources: national turnaround channels (such as HBO, ESPN and CNN) and various local channels (NBC, CBS, ABC, PBS and Fox affiliates in a particular area). Most of the turnaround channels also provide programming for cable television, and the local channels ty
18、pically broadcast their programming over the airwaves. Turnaround channels usually have a distribution centre that beams their programming to a geostationary satellite. The broadcast centre uses large satellite dishes to pick up these analogs and digital signals from several sources. The broadcast c
19、entre converts all of this programming into a high-quality, uncompressed digital stream. At this point, the stream contains a vast quantity of dataabout 270 megabits per second (Mbps) for each channel. In order to transmit the signal from there, the broadcast centre has to compress it. Otherwise, it
20、 would be too big for the satellite to handle. Compression, Encryption and Transmission The two major providers in the United States use the MPEG-2 compressed video format the same format used to store movies on DVDs. With MPEG-2 compression, the provider can reduce the 270-Mbps stream to about 5 or
21、 10 Mbps (depending on the type of programming). This is the crucial step that has made DBS service a success. With digital compression, a typical satellite can transmit about 200 channels. Without digital compression, it can transmit about 30 channels. At the broadcast centre, the high-quality digi
22、tal stream of video goes through an MPEG-2 encoder, which converts the programming to MPEG-2 video of the correct size and format for the satellite receiver in your house. After the video is compressed, the provider needs to encrypt it in order to keep people from accessing it for free. Encryption s
23、crambles the digital data in such a way that it can only be decrypted (converted back into usable data) if the receiver has the correct decryption algorithm and security keys. Once the signal is compressed and encrypted, the broadcast centre beams it directly to one of its satellites. The satellite
24、picks up the signal with an onboard dish, amplifies the signal and uses another dish to beam the signal back to the Earth, where viewers can pick it up. The Dish and the Receiver A satellite dish is just a special kind of antenna designed to focus on a specific broadcast source. The standard dish co
25、nsists of a parabolic (bowl-shaped) surface and a central feed horn. To transmit a signal, a controller sends it through the horn, and the dish focuses the signal into a relatively narrow beam. The end component in the entire satellite TV system is the receiver. The receiver has four essential jobs:
26、 It de-scrambles the encrypted signal. In order to unlock the signal, the receiver needs the proper decoder chip for that programming package. It takes the digital MPEG-2 signal and converts it into an analog format that a standard television can recognize. In the United States, receivers convert th
27、e digital signal to the analog NTSC format. Some dish and receiver setups can also output an HDTV signal. It extracts the individual channels from the larger satellite signal. When you change the channel on the receiver, it sends just the signal for that channel to your TV. It keeps track of pay-per
28、-view programs and periodically phones a computer at the providers headquarters to communicate billing information. While digital broadcast satellite service is still lacking some of the basic features of conventional cable (the ability to easily split signals between different TVs and VCRs, for exa
29、mple), its high-quality picture, varied programming selection and extended service areas make it a good alternative for some. With the rise of digital cable, which also has improved picture quality and extended channel selection, the TV war is really heating up. 2 Broadcast stations use _to transmit
30、 radio waves to the surrounding area. （ A） a powerful antenna （ B） a much smaller antenna （ C） satellite dishes （ D） cable 3 The television satellites stay in geosynchronous orbit and_. （ A） transmit signal in the direct “line of sight“ （ B） compress the signal （ C） keep pace with the moon （ D） keep
31、 pace with the earth 4 In recent years, satellite television has started to be broadcast in the radio frequency range_. （ A） between 3.4 GHz and 7 GHz （ B） between 12 GHz and 14 GHz （ C） between 14 GHz and 21 GHz （ D） between 21 GHz and 27GHz 5 Local television channels usually use _to transmit thei
32、r programming. （ A） satellites （ B） cable （ C） airwaves （ D） wires 6 Satellite television providers can bring dozens or even hundreds of channels to TV viewers because_. （ A） satellite can send more programs （ B） the television signals sent to satellites are compressed （ C） the signals are encrypted
33、 （ D） the signals converted back into usable data 7 _receives satellite television signal and decodes it for the TV screen. （ A） The satellite dish （ B） The provider （ C） The receiver （ D） The viewer 8 Satellite TV has encountered fierce competition from digital cable, which also has （ A） improved p
34、icture quality （ B） extended channel selection （ C） distorted signal （ D） both A and B 9 Satellite television is similar to broadcast television in the way that it is _for sending television programming directly to a viewers home. 10 In the United States, the two major providers of direct broadcast
35、satellite television are_. 11 The satellite television signal is transmitted in the digital video format of_. Section A Directions: In this section, you will hear 8 short conversations and 2 long conversations. At the end of each conversation, one or more questions will be asked about what was said.
36、 Both the conversation and the questions will be spoken only once. After each question there will be a pause. During the pause, you must read the four choices marked A, B, C and D, and decide which is the best answer. （ A） It was so-so. （ B） It was expensive. （ C） It was lost. （ D） It was great. （ A
37、） Most of the mans friends are athletes. （ B） Few people share the womans opinion. （ C） The man doesnt look like a sportsman. （ D） The woman doubts the mans athletic ability. （ A） Go to the library. （ B） Meet the woman. （ C） See Professor Smith. （ D） Have a drink in the bar. （ A） Where is the manage
38、r now? （ B） Who will be his new manager? （ C） Whether his manager is ill. （ D） When the manager will go to the headquarters. （ A） He dislikes museums and galleries. （ B） He does not care about the hot weather. （ C） Going to the beach is the best choice. （ D） He doesnt want to go to Washington. （ A）
39、She wants to live in the suburbs. （ B） She is offended by her naughty children. （ C） She disagrees with father. （ D） She turns a deaf ear to her husbands words. （ A） She will choose a new topic to write the essay. （ B） She used to choose the poetry written by Shakespeare as the topic. （ C） She refus
40、es to accept the mans advice. （ D） She is on the wrong track. （ A） How to buy a good computer. （ B） How to borrow a computer from the company. （ C） The price of the computer. （ D） The newly-bought computer. （ A） Pollution problem. （ B） Population problem. （ C） Unemployment problem. （ D） Nuclear weap
41、on problem. （ A） To state strongly that it is illegal to demonstrate. （ B） To reiterate the opinion that the demonstration is for the wrong cause. （ C） To convince the man that the issues are really complex. （ D） To support her reasoning for not going to a demonstration. （ A） She cannot believe the
42、fact that all the students in a class decided to go to the demonstration. （ B） She is sure that there isnt a wonderful leader in any class to lead other students. （ C） She wants to know exactly who the oratory leader in the class is. （ D） She feels that she is left out. （ A） It wastes time. （ B） It
43、is enjoyable. （ C） It benefits the class. （ D） It is good but needs improving. （ A） It offers students a chance to speak and share their minds. （ B） It helps students sit there and listen more carefully. （ C） It gives teachers more time to prepare for class. （ D） It can be organized by students them
44、selves. （ A） Because he expects the professor to give him a good score. （ B） Because the professor is expected to be better informed. （ C） Because he respects the professors reputation. （ D） Because the professor expects him to do so. （ A） The man and the woman have the same opinion about the class
45、discussion. （ B） It is usually too noisy to bear the class discussion; （ C） Many students pay no attention to the class discussion. （ D） Some students in the class discussion are self-important and irritating. Section B Directions: In this section, you will hear 3 short passages. At the end of each
46、passage, you will hear some questions. Both the passage and the questions will be spoken only once. After you hear a question, you must choose the best answer from the four choices marked A, B, C and D. （ A） An unexpected event that happens. （ B） Your understanding of an event. （ C） The things that
47、happen in our lives. （ D） The mentioning of the word itself. （ A） When we are tired. （ B） When we have a balanced diet. （ C） When we can relax. （ D） When we do regular exercise. （ A） Going to bed earlier. （ B） Working even harder, （ C） Reading more books. （ D） Finding its cause. （ A） Listening to sk
48、illed peoples advice. （ B） Asking older people many questions. （ C） Making mistakes and having them corrected. （ D） Learning what other people do without being taught. （ A） Teach the students the right way of thinking, （ B） Point out the students mistakes and correct them. （ C） Give the students cor
49、rect answers and let them work on their own. （ D） Do some routine work. （ A） Allow children to learn from each other. （ B） Point out childrens mistakes whenever found. （ C） Correct the childrens mistakes as soon as possible. （ D） Give children more book knowledge. （ A） The difficulties in teaching spelling. （ B） The role of spelling in general language development. （ C） The complexities of the basic writing skills. （ D） The necessity of teaching spelling. （ A） Because students will he able to e
