单选题Almost everyone at the meeting has different {{U}}views{{/U}}.

单选题Jack is a diligent worker.

单选题Superconductor Ceramic (陶瓷) An underground revolution begins this winter. With the flip (轻击) of a switch, 30,000 homes in one part of Detroit will soon become the first in the country to receive electricity transmitted by ice cold high performance cables. Other American cities are expected to follow Detroit"s example in the years ahead, which could conserve enormous amounts of power. The new electrical cables at the Frisbie power station in Detroit are revolutionary because they are made of superconductors. A superconductor is a material that transmits electricity with little or no resistance. Resistance is the degree to which a substance resists electric current. All common electrical conductors have a certain amount of electrical resistance. They convert at least some of the electrical energy passing through them into waste heat. Superconductors don"t. No one understands how superconductivity works. It just does. Making superconductors isn"t easy. A superconductor material has to be cooled to an extremely low temperature to lose its resistance. The first superconductors, made more than 50 years ago, had to be cooled to -263 degrees Celsius before they lost their resistance. Newer superconducting materials lose their resistance at -143 degrees Celsius. The superconductors cable installed at the Frisbie station is made of a ceramic material that contains copper, oxygen, bismuth (铋), strontium (锶), and calcium (钙). A ceramic is a hard, strong compound made from clay or minerals. The superconducting ceramic has been fashioned into a tape that is wrapped lengthwise around a long tube filled with liquid nitrogen. Liquid nitrogen is super cold and lowers the temperature of the ceramic tape to the point where it conveys electricity with zero resistance. The United States loses an enormous amount of electricity each year to resistance. Because cooled superconductors have no resistance, they waste much less power, other cities are watching the Frisbie experiment in the hope that they might switch to superconducting cable and conserve power, too.

单选题Electric Backpack Backpacks are convenient. They can hold your books, your lunch, and a change of clothes leaving your hands free to do other things. Someday, if you don't mind carrying a heavy load, your backpacks might also power your MP3 player, keep your cell phone running, and maybe even light your way home. Lawrence C. Rome and his colleagues from the University of Pennsylvania in Philadelphia and the Marine Biological Laboratory in WoodsHole, Mass. have invented a backpack that makes electricity from energy produced while its wearer walks. In military actions search-and-rescue operations and scientific field studies, people rely increasingly on cell phones global positioning system (GPS) receivers, night-vision goggles, and other battery powered devices to get around and do their work. The backpack's electricity-generating feature could dramatically reduce the amount of a wearer's load now devoted to spare batteries, report Rome and his colleagues in the Sept.9 science. The backpack's electricity-creating powers depend on springs used to hang a cloth pack from its metal frame. The frame sits against the wearer's back, and the whole pack moves up and down as the person walks. A gear mechanism converts vertical movements of the pack to rotary motions of an electrical generator, producing up to 7.4 watts. Unexpectedly, tests showed that wearers of the new backpack alter their gaits in response to the pack's oscillations, so that they carry loads more comfortably and with less effort than they do ordinary backpacks. Because of that surprising advantage, Rome plans to commercialize both electric and non-electric versions of the backpack. The backpack could be especially useful for soldiers, scientists, mountaineers, and emergency workers who typically carry heavy backpacks. For the rest of us, power-generating backpacks could make it possible to walk, play video games, watch TV, and listen to music, all at the same time. Electricity-generating packs aren't on the market yet, but if you do get one eventually just make sure to look both ways before crossing the street!

单选题{{B}}第二篇{{/B}} Valuing Childhood The value of childhood is easily hturred (变得模糊不清) in today's world. Consider some recent developments: The child-murderers in the Jonesboro, Ark. schoolyard shooting case were convicted and sentenced. Two boys, 7 and 8, were charged in the murder of an 11-year-old girl in Chicago. Children who commit horrible crimes appear to act of their own will. Yet, as legal proceedings in Jonesboro showed, the one boy who was able to address the court couldn't begin to explain his acts, though he tried to apologize. There may have been a motive-youthful jealousy(妒忌) and resentment. But a deeper question remains. Why did these boys and others in similar trouble apparently lack any inner, moral restraint? That question echoes for the accused in Chicago, young as they are. They wanted the girl's bicycle, a selfish impulse common enough among kids. Redemption (拯救) is a practical necessity. How can value be restored to young lives distorted by acts of violence? The boys in Jonesboro and in Chicago will be confined in institutions for a relatively short time. Despite horror at what was done, children are not-cannot be-dealt with as adults, not if a people wants to consider itself civilized. That's why politicians' cries for adult treatment of youthful criminals ultimately miss the point. But the moral void(真空)that invites violence has many sources. Family instability con-tributes. So does economic stress. That void, however, can be filled. The work starts with parents, who have to ask themselves whether they're doing enough to give their children a firm sense of right and wrong. Are they really monitoring their activities and their developing processes of thought? Schools, too, have a role in building character. So do youth organizations. So do law enforcement agencies, which can do more to inform the young about laws, their meaning, and their observance (遵守). The goal, ultimately, is to allow all children a normal passage from childhood to adulthood (成 年), so that tragic gaps in moral judgement are less likely to occur. The relative few who fill such gaps with acts of violence hint at many others who don't go that far, but who lack the moral foundations childhood should provide-and which progressive human society relies on.

单选题Mars Probe Watches Water-ice Fade The pictures acquired by a NASA orbiter(卫星) show white material exposed by flesh meteorite impacts fading over time-behaviour expected of ice on Mars. An onboard instrument also detected the tell-tale chemical signature of water. To date, exposed water-ice has only been seen at very high latitudes. The US space agency's (NASA) recent Phoenix probe famously dug into water-ice at its" high Arctic" landing site. The implication, even with the small set of examples scientists now have, is that broad deposits of ice sit just below the red top-soil of Mars. "There's a consistent picture starting to emerge now that these broad sheets may be common on Mars," observed Shane Byme of the University of Arizona, a member of the team running the HiRISE camera on NASA's Mars Reconnaissance Orbiter (MRO). "The volume of water is probably comparable to the volume that we would have in the Greenland ice sheet on the Eanh-in the buried ice deposits that stretch from each pole to mid-latitudes. " MRO has produced" earlier" and" later" images at five fresh impact sites made in 2008. These were all halfway between the North Pole and the equator on Mars. The craters (环形山, 陨石坑) were small, just a few metres across, gouged out by incoming space rocks that may have been no more than 10cm in size. The bright, white deposits uncovered by the impacts were seen to wither over time, something exposed water-ice cannot help but do in the low-pressure Martian atmosphere. It is bound to sublimate-to tum directly from a solid into a Vapour. However, the length of time it took to fade was a good indication that the ice was very pure. Had it contained a lot of dirt mixed in with it, the ice would have sublimated much quicker, scientists said. The discoveries made by MRO are said to indicate that Mars had a more humid climate in the relatively recent past, within the last 10,000 years. Scientists suspect much of this ice came out of the atmosphere. Water vapour in the atmosphere will diffuse through the particles of the soil until it gets to a certain depth where it then freezes. The locations of the exposed ice fit with the models used to predict where ground ice might be stable, i. e. from mid up to high latitudes. "The more humid the Martian atmosphere, the more extensive the area of this stable ice. " explained Shane Byme. "Based on the locations of these craters, we are able to say something about how much water was in the Martian atmosphere recently, and that turns out to be a lot more than is in the atmosphere today—maybe almost double what's in the atmosphere today. /

单选题Techniques to employ the energy of the sun are being developed.

单选题Do not waste time on insignificant points.

单选题World Crude Oil Production May Peak Decade Earlier Than Some Predict In a finding that may speed efforts to conserve oil, scientists in Kuwait predict that world conventional crude oil production will peak in 2014. This prediction is almost a decade earlier than some other predictions. Their study is in ACS' Energy & Fuels. lbrahim Nashawi and colleagues point out that rapid growth in global oil consumption has sparked a growing interest in predicting "peak oil". "Peak oil" is the point where oil production reaches a maximum and then declines. Scientists have developed several models to forecast this point, and some put the date at 2020 or later. One of the most famous forecast models is called the Hubbert model. It assumes that global oil production will follow a bell shaped curve. A related concept is that of "Peak Oil". The term "Peak Oil" indicates the moment in which world wide production will peak, afterwards to start on irreversible decline. The Hubbert model accurately predicted that oil production would peak in the United States in 1970. The model has since gained in popularity and has been used to forecast oil production worldwide. However, recent studies show that the model is insufficient to account for more complex oil production cycles of some countries. Those cycles can be heavily influenced by technology changes, politics, and other factors, the scientists say. The new study describes development of a new version of the Hubbert model that provides a more realistic and accurate oil production forecast. Using the new model, the scientists evaluated the oil production trends of 47 major oil-producing countries which supply most of the world's conventional crude oil. They estimated that worldwide conventional crude oil production will peak in 2014, years earlier than anticipated. The scientists also showed that the world's oil reserves are being reduced at a rate of 2.1 percent a year. The new model could help inform energy-related decisions and public policy debate, they suggest.

单选题 Sino-Japan Animosity Lessens Chinese and Japanese people view each other slightly more positively than last year, according to a survey released on Wednesday at a press conference in Beijing. The survey is jointly sponsored by China Daily and Genron NPO, a Japanese think tank similar to the American Council on Foreign Relations. It also found overwhelming agreement in both countries that Sino-Japanese relations were important. The survey is a part of the Beijing-Tokyo Forum, an annual gathering of senior government officials and representatives from Chinese and Japanese NGOs designed to improve communication and understanding between the two countries. Conducted every year for five years now, the survey focused on two different groups of people: ordinary citizens, and intellectuals. In China, the intellectual group was comprised mainly of university students from well-known schools like Peking University. In Japan, the "intellectual" group was mainly made up of previous members of Genron NPO. Among ordinary Chinese polled, 35.7 percent said they have "very good" or "relatively good" impressions of Japan, a 5.5-percentage-point increase compared with last year. 45.2 percent of Chinese students had a positive impression of Japan, two percentage points more than last year. Only 26.6 percent of Japanese have a positive impression of China, however. Still, an overwhelming majority of the respondents from each country said Sino-Japanese relations were "important" and wanted their leaders to deepen talks and cooperation with each other. But 51.9 percent of ordinary people and 42.4 percent of students in China said they saw no change in relations between the two countries over the last year. In Japan, 64.8 percent of those ordinary people and 53.4 percent of intellectuals surveyed shared the view that there was no improvement in bilateral ties this year. Historical issues and territorial disputes remain two major obstacles to improving bilateral relations, the survey found. What concerns the Chinese most are historical issues, visits by Japanese officials to Yasukuni Shrine, and the Nanjing Massacre. Perceptions on economic and trade relations have improved, though. About 47 percent of ordinary Japanese said China had been "helpful" this year in fighting the global economic crisis, compared with just 30 percent last year. The percent of Japanese intellectuals who said Chinese economic growth was good for Japan increased from 65.8 percent to 81.4 percent this year. Cooperation in East Asian issues, trade and investment, energy, and the environment and climate change top the list of common concerns that people in China and Japan want their leaders to talk about in bilateral meetings, the survey found. Civil exchanges were regarded by the most people from the both countries as an important way to improve relations. 90.7 percent of the students and 85.7 percent of the ordinary people in China and 95.8% of intellectuals and 74.8% of the ordinary people in Japan viewed civil exchanges as "important" or "relatively important". Chinese and Japanese both learn about each other's countries mostly through television news and newspapers, the survey found.

单选题Controlling Robots with the Mind Belle, our tiny monkey, was seated in her special chair inside a chamber at our Duke University lab. Her right hand grasped a joystick (操纵杆) as she watched a horizontal series of lights on a display panel (显示面板). She knew that if a light suddenly shone and she moved the joystick left or right to correspond to its position, she would be sent a drop of fruit juice into her mouth. Belle wore a cap glued to her head. Under it were four plastic connectors, which fed arrays of microwires—each wire finer than the finest sewing thread—into different regions of Belle"s motor cortex (脑皮层), the brain tissue that plans movements and sends instructions. Each of the 100 microwires lay beside a single motor neuron (神经元). When a neuron produced an electrical discharge, the adjacent microwire would capture the current and send it up through a small wiring bundle that ran from Belle"s cap to a box of electronics on a table next to the booth. The box, in turn, was linked to two computers, one next door and the other half a country away. After months of hard work, we were about to test the idea that we could reliably translate the raw electrical activity in a living being"s brain—Belle"s mere thoughts—into signals that could direct the actions of a robot. We had assembled a multijointed robot arm in this room, away from Belle"s view, which she would control for the first time. As soon as Belle"s brain sensed a lit spot on the panel, electronics in the box running two real-time mathematical models would rapidly analyze the tiny action potentials produced by her brain cells. Our lab computer would convert the electrical patterns into instructions that would direct the robot arm. Six hundred miles north, in Cambridge, Mass, a different computer would produce the same actions in another robot arm built by Mandayam A. Srinivasan. If we had done everything correctly, the two robot arms would behave as Belle"s arm did, at exactly the same time. Finally the moment came. We randomly switched on lights in front of Belle, and she immediately moved her joystick back and forth to correspond to them. Our robot arm moved similarly to Belle"s real arm. So did Srinivasan"s. Belle and the robots moved in synchrony (同步), like dancers choreographed (设计舞蹈动作) by the electrical impulses sparking in Belle"s mind. In the two years since that day, our labs and several others have advanced neuroscience, computer science and microelectronics to create ways for rats, monkeys and eventually humans to control mechanical and electronic machines purely by "thinking through", or imagining, the motions. Our immediate goal is to help a person who has been unable to move by a neurological (神经的) disorder or spinal cord (脊髓) injury, but whose motor cortex is spared, to operate a wheelchair or a robotic limb.

单选题Our lives are Uintimately/U bound up with theirs.

单选题 下面有3篇短文，每篇短文后有5道题，每道题后面有4个选项。请仔细阅读短文引：根据短文回答其后面的问题，从4个选项中选择1个最佳答案填入题前的括号内。{{B}}第一篇{{/B}} {{B}}New Foods and the New World{{/B}} In the last 500 years, nothing about people — not their clothes, ideas, or languages — has changed as much as what they eat. The original chocolate drink was made from the seeds of the cocoa tree (可可树) by South American Indians. The Spanish introduced it to the rest of the world during the 1500's. And although it was very expensive, it quickly became fashionable. In London, shops where chocolate drinks were served became important meeting places. Some still exist today. The potato is also from the New World. Around 1600, the Spanish brought it from Peru to Europe, where it soon was widely grown. Ireland became so dependent on it that thousands of Irish people starved when the crop failed during the "Potato Famine (饥荒)" of 1845 — 1846, and thousands more were forced to leave their homeland and move to America. There are many other foods that have traveled from South America to the Old World. But some others went in the opposite direction. Brazil is now the world's largest grower of coffee, and coffee is an important crop in Colombia and other South American countries. But it is native to Ethiopia, a country in Africa. It was first made into a drink by Arabs during the 1400's. According to an Arabic legend, coffee was discovered when a person named Kaldi noticed that his goats were attracted to the red berries on a coffee bush. He tried one and experienced the "wide-awake" feeling that one-third of the world's population now starts the day with.

单选题For many people today, reading is no longer relaxation. In (51) a job or advancing in one, the ability to read and comprehend (52) can mean the difference between success and failure. Yet the unfortunate, fact is that most of us are (53) readers. Most of us develop poor reading (54) at an early age, and never get over them. The main deficiency (55) in the actual stuff of language itself-words. Taken individually, words have little meaning until they are strung together into phrased, sentences and paragraphs. (56) however, the untrained reader does not read groups of words, He laboriously reads one word at a time, often regressing to (57) words or passages. Regression, the tendency to look back over (58) you have just read, is a common bad habit in reading. Another habit which (59) down the speed of reading is vocalization-sounding each word either orally or mentally as one reads. To overcome these bad habits, some reading clinics use a device called all (60) , which moves a bar( or curtain)down the page at a predetermined speed. The accelerator forces the reader to read fast, (61) word-by-word reading, regression and sub-vocalization, practically impossible. At first comprehension is sacrificed for speed. But when you learn to read ideas and concepts, you will not only read faster (62) your comprehension will improve. Many people have found-their reading skill drastically improved after some training. (63) Charlce Au, a business manager, for instance, his reading rate was a reasonably good 172 words a minute (64) the training, now it is an excellent 1,378 words a minute. He is delighted that how he can (65) a lot more reading material in a short period of time.

单选题Department Store A mainstay of retailing in the United States is the department store, a large-scale retailing instituting that has a very broad and deep product assortment (分类), tires not to compete on the basis of price, and provides a wide array or customer services. Traditional department stores offer a greater variety of merchandise and services than does any other type of retail store. They feature both "soft goods"—such as apparel, sheets, towels, and bedding (寝具)—and "hard goods" including furniture, appliances, and consumer electronics. Department stores also attract—and satisfy consumers by offering many customer services. The combination of distinctive, appealing merchandise and numerous customer services is designed to allow the stores to maintain the manufacturers' suggested retail prices. That is, department stores strive to charge" full" or "nondiscounted" (不打折扣的) prices. Department stores face mounting problems, however, Largely due to their prime locations and customer services, their operation expenses are considerably higher than those of most other kinds of retail business. Many manufacturers 'brands that used to be available exclusively thorough department stores are now widely distributed and often carry discounted prices in other outlets. And the quality of personal service, especially knowledgeable sales help, has deteriorated in some department stores. Intense horizontal competition is also hurting department stores. Other types of retailers are aiming at consumers who have long supported department stores. Speciality stores, off-price retailers, and even some discount houses have been particularly aggressive in trying to lure shoppers sway from department stores. To varying degrees retail chains compete against department stores. Consequently, many department stores have modified their target markets or elements of their marketing mixes. The May Department Stores Company has targeted middle-income consumers, rejecting high-priced European designer lines and instead concentrating on fashionable apparel with moderate prices. Penney's dropped three lines of hard goods—home electronics, sporting goods, and photographic equipment. Penney's, Ward's, and Sears are all converting their very large stores into a collection of limited-line "superstores". Some department stores are also trying to be more price-competitive. Most notably, in 1989 Sears abandoned its practice of promoting temporarily reduced prices and adopted a strategy of "everyday low prices". With this policy, prices will always be lower than or as low as competitors.

单选题She stood there, shaking with Ufury/U.

单选题Prolonging Human Life Prolonging human life has increased the size of the human population. Many people alive today would have died of childhood diseases if they had been born 100 years ago. Because more people live longer, there are more people around at any given time. In fact, it is a decrease in death rates, not an increase in birthrates, that has led to the population explosion. Prolonging human life has also increased the dependency load. In all societies, people who are disabled or too young or too old to work are dependent on the rest of society to provide for them. In hunting and gathering cultures, old people who could not keep up might be left behind to die. In times of famine, infants might be allowed to die because they could not survive if their parents starved, whereas if the parents survived they could have another child. In most contemporary societies, people feel a moral obligation to keep people alive whether they can work or not. We have a great many people today who live past the age at which they want to work or are able to work; we also have roles which require people to retire at a certain age. Unless these people were able to save money for their retirement, somebody else must support them. In the United States many retired people live on social security checks which are so little that they must live in near poverty. Older people have more illness than young or middle-aged people; unless they have wealth or private or government insurance, they must often "go on welfare” if they have a serious illness. When older people become senile or too weak and ill to care for themselves, they create grave problems for their families. In the past and in some traditional cultures, they would be cared for at home until they died. Today, with must members of a household working or in school, there is often no one at home who can care for a sick or weak person. To meet this need, a great many nursing homes and convalescent hospitals have been built. These are often profit-making organizations, although some are sponsored by religious and other nonprofit groups. While a few of these institutions are good, most of them are simply "dumping grounds" for the dying in which "care" is given by poorly paid, overworked, and underskilled personnel.

单选题Biologists have {{U}}ascertained{{/U}} that specialized cells convert Chemical energy into mechanical energy.

单选题The game requires us to find out two simple but effective ways to solve this problem.

单选题Doctors have found that laughter