1、大学英语六级模拟试卷 721及答案与解析 一、 Part I Writing (30 minutes) 1 Direction： For this part, you are allowed 30 minutes to write a short essay entitled The Phenomenon of Empty Nest. You should write at least 150 words following the outline given below. “空巢老人 ”指那些到了退 休年龄，身边却无子女与之共同生活的老人。 1如今的空巢老人逐渐增多 2这种现象出现的原因 3
2、如何解决由此带来的问题 The Phenomenon of Empty Nest 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 agr
3、ees 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 Beijing 2008: The First 4G Wireless Olympic Games ? About half a million years ago, Peking man lived in Zh
4、oukoudian, in the southwestern suburbs of what is now Beijing. If you have been to Beijing more recently, or are at all familiar with modern China, then you know this ancient city is going to host the most modern, high-tech Olympic Games ever in 2008. With technology available today, and a vision fo
5、r what Beijing could be in 2008, there is an opportunity for the hosts to make the citys telecommunications infrastructure-in the words of the Olympic motto “swifter, higher, stronger“. The Path to 4G Beijing has the good fortune of looking at previous generations of wireless networks and avoiding t
6、he same mistakes as it prepares for 2008. First Generation (1G) wireless telecommunications the brick-like analog phones that are now collectors itemsintroduced the cellular architecture that is still being offered by most wireless companies today. Second Generation (2G) wireless supported more user
7、s within a cell by using digital technology, which allowed many callers to use the same multiplexed channel. But 2G was still primarily meant for voice communications, not data, except some very low data-rate features, like Short Messaging Service (SMS). So-called 2.5G allowed carriers to increase d
8、ata rates with a software upgrade at the base transceivers Stations (BTS), as long as consumers purchased new phones too. Third Generation (3G) wireless offers the promise of greater bandwidth, basically bigger data pipes to users, which will allow them to send and receive more information. All of t
9、hese architectures, however, are still cellular. Cellular architecture is sometimes referred to as a “star architecture, because users within that cell access a common, centralized base station. The advantage is that given enough time and money, carriers can build nationwide networks, which most of
10、the big carriers have done. Some of the disadvantages include a singular point of failure, no lead balancing, and spectral inefficiencies. The single biggest disadvantage to cellular networks going forward is that as data rates increase, output power will have to increaseor the size of the cells win
11、 have to decreaseto support those higher data rates. Since significant increases in output power scare both consumers and regulators, it is far more likely that we will see significantly smaller cells. This will further reduce the return on investment in already fragile 3G business plans. Fourth Gen
12、eration (4G) wireless was originally conceived by the Defense Advanced Research projects Agency (DARPA), the same organization that developed the wired Internet. It is not surprising, then, that DARPA chose the same distributed architecture for the wireless Internet that had proven so successful in
13、the wired Internet. Although experts and policymakers have yet to agree on all the aspects of 4G wireless, two characteristics have emerged as all but certain components of 4G:end-to-end Internet Protocol (IP) ,and peer-to-peer(点对点 )networking. An all IP network makes sense because consumers will wa
14、nt to use the same data applications they are used to in wired networks. Peer-to-peer networks, where every device is both a transceiver (收发机 ) and a router (路由器 ) for other devices in the network, eliminates the weakness of cellular architectures, because the elimination of a single node does not d
15、isable the network. The final definition of “4G“ will have to include something as simple as this: if a consumer can do it at home or in the office while wired to the Internet, that consumer must be able to do it wirelessly in a fully mobile environment. Lets define “4G“ as “wireless collaborated pe
16、er-to-peer networking“. 4G technology is significant because users joining the network add mobile routers to the network infrastructure. Because users carry much of the network with them, network capacity and coverage is dynamically shifted to accommodate changing user patterns. As people congregate
17、 and create pockets of high demand, they also create additional routes for each other, thus enabling additional access to network capacity. Users will automatically hop away from congested routes to less congested routes. This permits the network to dynamically and automatically self-balance capacit
18、y, and increase network utilization. What could 4G mean for Beijing and its Olympics? There is a Statistic (without any known attribution) that estimates that the first phone call made by a majority of Chinese alive today was with a cell phone. This would mean that most Chinese skipped a whole gener
19、ation of telephony (copper twisted pair) and jumped into the world of wireless telephony. So too might the Chinese skip a generation of wireless and deploy a 4G network before 2008. Following are a few applications that could further enhance the Olympic experience, both for the visitors during the G
20、ames, and for the residents of Beijing long afterwards. Security Beijing has already deployed cameras throughout the city and sends those images back to a central command center. This is generally done using fiber, which limits where the cameras can be hung, i.e., no fiber, no camera. 4G networks al
21、low Beijing to deploy cameras and backhaul(回传 ) them wirelessly. And instead of having to backhaul every camera, cities can backhaul every third or fifth or tenth camera, using the other cameras as router/repeater. Traffic Control Beijing is a challenging city for drivers, with or without an Olympic
22、s going on. The growing middle class, and their new-found ability to purchase automobiles, is increasing the number of passenger vehicles on the road at a staggering annual rate of 30%. 4G networks can connect traffic control boxes to intelligent transportation management systems wirelessly, This wo
23、uld create a traffic grid that could change light cycle times on demand, e.g. , keeping some lights green longer temporarily to improve traffic flow. It also could make vehicle-based on-demand “all green“ routes for emergency vehicles responding to traffic accidents, reducing the likelihood that tho
24、se vehicles will themselves be involved in an accident route. Hot Spots Beijing could deploy information kiosks(亭 )around the city to allow visitors to the Olympics to get real- time information on results, venue updates, and traffic conditions. They could, be backhauled to the Internet via existing
25、 cable or DSL. But they could also be home to 802.11 access points, providing free information to any- one with an 802.11 card. And with 4Gs peer-to-peer capabilities, the city could deploy access points even where there is no fiber, by having those “remote“ access points hop through backhauled acce
26、ss points. Mobile Hot Spots To exploit the real power of 4G, Beijing could create mobile hot spots. This would allow users in the sub- ways, trains, and buses to connect to the Internet via standard 802.11 cards talking to standard 802.11 access points. But since those access points obviously cannot
27、 be wired to the network, they are connected via 4G wireless networks. Conclusion Heating an Olympic Games is, well, an Olympian task. Modern China is more than up to the challenge and it is safe to predict that Beijing 2008 will be one of the most impressive Games of all times. But one other way to
28、 measure the success of the Games is the impact it has on the host city after the torch is extinguished. By deploying a 4G mobile broadband network for the Games, Beijing will ensure that its residents will enjoy profound and lasting benefits. 2 Because short messaging service is a kind of data comm
29、unication, second generation wireless cannot support it. 3 One of the great drawbacks of cellular networks is its expensive implementing cost. 4 The networks of communication system which are peer-to-peer are one property of 4G wireless communication. 5 If many people have demand for the network at
30、the same time, the data communication will be difficult even with 4G technology. 6 If somebody who is still alive receives a phone call from China, this call is very possibly dialed by _. 7 4G wireless communication can take the place of _ to send images back to central command center. 8 With the he
31、lp of 4G networks, traffic light cycle period can be adjusted according to _. 9 During Beijing Olympics, tourists can easily obtain the information about game results and traffic conditions in time from _. 10 Even on their way to destinations, travelers can easily surf Internet by 802.11 cards if th
32、ere are _. 11 Whether Beijing 2008 is successful or not can be ascertained by _ on Beijing after it is over. 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.
33、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） Not to go home for spring vacation. （ B） Not to take a vacation. （ C） Not to g
34、raduate. （ D） Not to go home after graduation in May. （ A） At a butcher shop. （ B） At a restaurant. （ C） At a bookstore. （ D） At a grocery store. （ A） Secretary-Boss. （ B） Client-Lawyer. （ C） Student-Teacher. （ D） Patient-Nurse. （ A） That the man will not be able to sleep. （ B） That someone will ent
35、er the back door while the man is sleeping. （ C） That the lock on the door will break. （ D） That the man will not be rifle to come back. （ A） $ 16. （ B） $ 12. （ C） $4. （ D） $2. （ A） The Best of Jazz. （ B） Christmas Carols. （ C） Classical Music. （ D） Rock Music Collection. （ A） It is closed. （ B） 12
36、noon to 9 P. M. （ C） 9A.M. to5 P.M. （ D） 9A.M. to 12 noon. （ A） Gensen. （ B） Jensen. （ C） Jinsin. （ D） Ginsin. （ A） How to drop a course. （ B） The man needs advice about which classes to take. （ C） How to get the approval of the professor. （ D） How to add a course to the mans schedule. （ A） He lost
37、his class schedule. （ B） He could not drop the astronomy course. （ C） He registered for too many classes. （ D） He missed the deadline for adding courses. （ A） Write an astronomy paper. （ B） Sign the form. （ C） Decide which course to add. （ D） Look for the astronomy professor. （ A） How to get rich in
38、 a day. （ B） How to invest money in the future. （ C） How to set clear goals for the future. （ D） How to carry out reasonable investments. （ A） Making a saving plan. （ B） Setting up a bank account. （ C） Setting clear investing goals. （ D） Making clear why to invest. （ A） The risks and potential rewar
39、ds of the products. （ B） The different kinds of investments. （ C） The importance of investments. （ D） The sum of investments. （ A） It is a place full of risks. （ B） It is a good place to invest in. （ C） It has up times as well as down times. （ D） It has more up times than down times. Section B Direc
40、tions: 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 four choices marked A, B, C and D. （ A） They have nothing
41、 to do with each other. （ B） They have something to do with each other. （ C） They help each other in a way. （ D） They depend on each other. （ A） Other living things change their environment while man doesnt. （ B） Man alters his environment while he is adapted to it, but other living things do not. （
42、 C） Other living things is not only adapted to their environment but also alters it. （ D） Man is only adapted to the environment but he doesnt alter it. （ A） The relationship between man and his environment. （ B） The relationship between living things and their environment. （ C） The relationship bet
43、ween man and living things. （ D） The relationship between mans brain and other living things. （ A） To inhibit loans. （ B） To control inflation. （ C） To inhibit consumption. （ D） To encourage personal saving. （ A） They are disadvantageous to poor people. （ B） They make the economy from bad to worse.
44、（ C） They adversely affect the international trade. （ D） They greatly affect the domestic industry. （ A） Poor people in India make up 40% of the population. （ B） India is one of the leading tourist destinations. （ C） India is trying to get out of the economic crisis. （ D） India is the worlds second
45、fastest-growing major economy. （ A） Silent reading had not been discovered. （ B） There were few places available for private reading. （ C） Few people could read for themselves. （ D） People relied on reading for entertainment. （ A） A change in the status of educated people. （ B） A change in the natur
46、e 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 books and newspapers. （ C） The effects of healthy reading. （ D） The value of different types of reading materials. （ A） Explai
47、n bow 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 s
48、hould listen carefully for its general idea. When the passage is read for the second time, you are required to fill in the blanks numbered from 36 to 43 with the exact words you have just heard. For blanks numbered from 44 to 46 you are required to fill in the missing information. For these blanks,
49、you can either use the exact words you have just heard or write down the 36 Mountain climbing is becoming a popular sport, but it is also a【 B1】 _ dangerous one. People can fall; they may also become ill. One of the most common dangers to climbers is altitude sickness, which can affect even very【 B2】 _ climbers. Altitude sickness usually begins when a climber goes above 8,000 or 9,000 feet. The higher one climbs, the less oxygen there is in the air. When people dont get enough oxygen, they often
