1、大学英语六级模拟试卷 80及答案与解析 一、 Part I Writing (30 minutes) 1 For this part, you are allowed 30 minutes to write a short essay on the topic Do We Need “Never give up“? You should write at least 150 words following the outline given below in Chinese: 1 “永不言 弃 ”一直被认为是一种积极的生活态度，是个人成功的关键因素 2但是，也有人认为适当的放弃才是明智的选择
2、3你对此的看法及理由 Do We Need “Never give up“? 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 agree
3、s with 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. 2 Bluetooth When you use computers, entertainment systems or telephones, the various pieces-and parts of the s
4、ystems make up a community of electronic devices. These devices communicate with each other using a variety of wires, cables, radio signals and infrared light(红外线 ) beams, and an even greater variety of connectors and plugs. The art of connecting things is becoming more and more complex every day. A
5、nd Bluetooth has now become a new popular method of connecting devices that can streamline the process. A Bluetooth connection is wireless and automatic, and it takes small-area networking to the next level by removing the need for user intervention and keeping transmission power extremely low to sa
6、ve battery power. Bluetooth Operation Bluetooth networking transmits data via low-power radio waves. It communicates on a frequency of 2.45 gigahertz(千兆赫 )(actually between 2.402 GHz and 2.480 GHz, to be exact). This frequency band has been set aside by international agreement for the use of industr
7、ial, scientific and medical devices(ISM). A number of devices that you may already use take advantage of this same radio-frequency band. Baby monitors(微型监视器 ), garage-door openers and the newest generation of cordless phones all make use of frequencies in the ISM band. One of the ways Bluetooth devi
8、ces avoid interfering with other systems is by sending out very weak signals of about 1 milliwatt. By comparison, the most powerful cell phones can transmit a signal of 3 watts. The low power limits the range of a Bluetooth device to about 10 meters (32 feet), cutting the chances of interference bet
9、ween your computer system and your portable telephone or television. Even with the low power, Bluetooth doesnt require line of sight between communicating devices. The walls in your house wont stop a Bluetooth signal, making the standard useful for controlling several devices in different rooms. Blu
10、etooth can connect up to eight devices simultaneously. With all of those devices in the same 10-meter (32-foot) radius, you might think theyd interfere with one another, but its un- likely. Bluetooth uses a technique called spread-spectrum(扩展频谱 ) frequency that makes it rare for more than one device
11、 to be transmitting on the same frequency at the same time. In this technique, a device will use 79 individual, randomly chosen frequencies within a designated range, changing from one to another on a regular basis. In the case of Bluetooth, the transmitters change frequencies 1,600 times every seco
12、nd, meaning that more devices can make full use of a limited slice of the radio spectrum. Since every Bluetooth transmitter uses spread-spectrum transmitting automatically, its unlikely that two transmitters will be on the same frequency at the same time. This same technique minimizes the risk that
13、portable phones or baby monitors will disrupt Bluetooth devices, since any interference on a particular frequency will last only a tiny fraction of a second. Piconets(个人域网络 ) Lets say you have a typical modern living room with the typical modern stuff inside. Theres an entertainment system with a st
14、ereo, a DVD player, a satellite TV receiver and a television; theres also a cordless telephone and a personal computer. Each of these systems uses Bluetooth, and each forms its own piconet to talk between the main unit and peripheral(外围设备 ). The cordless telephone has one Bluetooth transmitter in th
15、e base and another in the handset. The manufacturer has programmed each unit with an address that falls into a range of ad- dresses it has established for a particular type of device. When the base is first turned on, it sends radio signals asking for a response from any units with an address in a p
16、articular range. Since the handset has an address in the range, it responds, and a tiny network is formed. Now, even if one of these devices should receive a signal from another system, it will ignore it since its not from within the network. The computer and entertainment system go through similar
17、routines, establishing networks among addresses in ranges established by manufacturers. Once the networks are established, the systems begin talking among themselves. Each piconet hops randomly through the available frequencies, so all of the piconets are completely separated from one another. Now t
18、he living room has three separate networks established, each one made up of devices that know the address of transmitters it should listen to and the address of receivers it should talk to. Since each network is changing the frequency of its operation thousands of times a second, its unlikely that a
19、ny two networks will be on the same frequency at the same time. If it turns out that they are, then the resulting confusion will only cover a tiny fraction of a second, and software designed to correct for such errors weeds out the confusing information and gets on with the networks business. Blueto
20、oth Security In any wireless networking setup, security is a concern. Devices can easily grab radio waves out of the air, so people who send sensitive information over a wireless connection need to take precautions to make sure those signals arent intercepted. Bluetooth technology is no different it
21、s wireless and therefore susceptible to spying and remote access, just like Wi-Fi is susceptible if the network isnt secure. With Bluetooth, though, the automatic nature of the connection, which is a huge benefit in terms of time and effort, is also a benefit to people looking to send you data witho
22、ut your permission. Bluetooth offers several security modes, and device manufacturers determine which mode to include in a Bluetooth-enabled gadget(配件 ). In almost all cases, Bluetooth users can establish “trusted devices“ that can exchange data without asking permission. When any other device tries
23、 to establish a connection to the users gadget, the user has to decide to allow it. Service level security and device-level security work together to protect Bluetooth devices from unauthorized data transmission. Security methods include authorization and identification procedures that limit the use
24、 of Bluetooth services to the registered user and require that users make a conscious decision to open a file or accept a data transfer. As long as these measures are enabled on the users phone or other device, unauthorized access is unlikely. A user can also simply switch his Bluetooth mode to “non
25、-discoverable“ and avoid connecting with other Bluetooth devices entirely. If a user makes use of the Bluetooth network primarily for synching devices at home, this might be a good way to avoid any chance of a security breach while in public. Still, early cell-phone virus writers have taken advantag
26、e of Bluetooths automated connection process to send out infected files. However, since most cell phones use a secure Bluetooth connection that requires authorization and authentication before accepting data from an unknown device, the infected file typically doesnt get very far. Other problems like
27、 “bluejacking“, “bluebugging“ and “Car Whisperer“ have turned up as Bluetooth-specific security issues. Like a computer security hole, these vulnerabilities are an inevitable result of technological innovation, and device manufacturers are releasing firmware upgrades that address new problems as the
28、y arise. 2 Bluetooth is changing small-area networking into a wireless and automatic connection with no need for user intervention and low need of transmission power. （ A） Y （ B） N （ C） NG 3 Bluetooth networking transmits data via low-power radio waves between 2.402 GHz and 2.480 GHz. （ A） Y （ B） N
29、（ C） NG 4 Making sure that Bluetooth and its connected devices dont interfere with one another can be difficult. （ A） Y （ B） N （ C） NG 5 With the development of spread-spectrum technique, we may use Bluetooth connection as a substitute for cell phone. （ A） Y （ B） N （ C） NG 6 Any two networks in pico
30、nets is unlikely to be on the same frequency simultaneously because each network is changing its _ thousands of times a second. 7 Manufacturers have developed _ to correct errors like receiving signal of the same frequency from a strange device. 8 Security is als0 a big concern as Bluetooth technolo
31、gy has an essence of _. 9 People can send you data without your permission because the Bluetooth connection is _. 10 One security mode offered by Bluetooth is that data may be exchanged freely among the devices Bluetooth users establish as _. 11 Vulnerabilities of Bluetooth like “bluejacking“ are _
32、in the development of technology. 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. Both the conversation and the questions will be spoken only once. After eac
33、h 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） Shes happy that the student center is getting more computers. （ B） Shell let the man use her computer to do statistics assignments. （ C） She will take a
34、statistics course in the student center soon. （ D） Shed like to buy a computer very soon. （ A） She is very happy to obey the rules. （ B） She is very interested in the rules. （ C） She is irritated by so many rules. （ D） She is sorry for the rules. （ A） Public Buses are fast and cheap transportation t
35、ools. （ B） Parking is becoming a big problem. （ C） Subway trains are even safer than taxies. （ D） Taxies are more convenient than buses. （ A） Hes also interested in American literature. （ B） He hasnt decided if he would take the literature class. （ C） The woman should have already finished her paper
36、. （ D） The womans topic may not be appropriate. （ A） She feels sorry owing to the mans failure. （ B） She did no better than the man in the contest. （ C） She is optimistic that she wont be the last in the contest. （ D） She thinks that they can win in the coming contest. （ A） It wont be different from
37、 the others. （ B） It will be unusually mild. （ C） It will be warm and comfortable. （ D） It. will probably be cold. （ A） By learning English alone. （ B） By learning English hard before test. （ C） By studying at her spare time. （ D） By learning a little regularly. （ A） She is a little tired. （ B） She
38、is going to study in the library. （ C） She wants to listen to the music. （ D） She is going to make a reservation. （ A） Current issues in economics. （ B） Choices faced by conservationists. （ C） A recent biology lecture. （ D） Topics for a research paper. （ A） A scarcity of jobs in their field. （ B） In
39、adequate training in methods of biological research. （ C） Difficulties in classifying all of the varieties of owls. （ D） A lack of funding for their work with endangered species. （ A） It has numerous traits in common with the spotted owl. （ B） Its population is increasing in recent years. （ C） It ma
40、y not survive without special efforts of conservationists. （ D） Its role in the chain of evolution has not yet been examined. （ A） They are looking for an apartment to live in. （ B） They are discussing living places and childrens education. （ C） They are complaining about their children. （ D） They a
41、re planning for the next weekend. （ A） Theres much to do besides work and study. （ B） Its convenient for people to go anywhere. （ C） The natural environment is beneficial to children. （ D） The countryside is a perfect place for weekends. （ A） The children are too young to benefit from city life. （ B
42、） Even adults themselves cannot go everywhere in the city. （ C） There is a lot to see and do for children and adults. （ D） There isnt a lot to see and do for children. （ A） She is a full-time housewife. （ B） She does not care for her children. （ C） She used to live in the suburbs in her childhood. （
43、 D） She will go to a museum next weekend. Section B Directions: In this section, you will hear 3 short passages. At the end of each 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
44、four choices marked A, B, C and D. （ A） They were evident in the decreased world temperature. （ B） They were of several days duration worldwide. （ C） They were felt mainly in the Dutch East Indies. （ D） They were immediately evident to the worlds scientists. （ A） Englands proximity to the sea. （ B）
45、Volcanic ash in the atmosphere. （ C） Flooding in the area. （ D） Pollution caused by the International Revolution. （ A） There was a long interval between cause and effect. （ B） The weather was difficult for us to forecast. （ C） Weather forecast was inaccurate. （ D） Ecologists didnt appear until moder
46、n times. （ A） A government document. （ B） A literary work. （ C） A social art. （ D） An individuals creation. （ A） Because they were not easily burned and can last long. （ B） Because they were very cheap materials. （ C） Because they could be found here and there. （ D） Because they could add artistic v
47、alue to buildings. （ A） Architecture and Literature. （ B） Development of Architecture. （ C） Classification of Architecture. （ D） Materials of Architecture. （ A） Silent reading had not been discovered. （ B） There were few places available for private reading. （ C） Few people could read for themselves
48、. （ D） People relied on reading for entertainment. （ A） A change in the status of educated people. （ B） A change in the nature of reading. （ C） An increase in the number of books. （ D） An increase in the average age of readers. （ A） The importance of silent reading. （ B） The information yielded by b
49、ooks and newspapers. （ C） The effects of healthy reading. （ D） The value of different types of reading materials. （ A） Explain how present-day reading habits developed. （ B） Change peoples attitudes to reading. （ C） Show how reading methods have been improved. （ D） Encourage the growth of reading. Section C Directions: In this section, you will hear a passage three times. When the passage is read for the first time, you shou
