单选题 If open-source software is supposed to be free, how does anyone selling it make any money? It's not that different from how other software companies make money. You'd think that a software company would make most of its money from, well, selling software. But you'd be wrong. For one thing, companies don't sell software, strictly speaking; they license it. The profit margin on a software license is nearly 100 percent, which is why Microsoft gushes billions of dollars every quarter. But what's the value of a license to a customer? A license doesn't deliver the code, provide the utilities to get a piece of software running, or answer the phone when something inevitably goes wrong. The value of software, in short, doesn't lie in the software alone. The value is in making sure the soft ware does its job. Just as a traveler should look at the overall price of a vacation package instead of obsessing over the price of the plane ticket or hotel room, a smart tech buyer won't focus on how much the license costs and ignore the support contract or the maintenance agreement. Open-source is not that different. If you want the software to work, you have to pay to ensure it will work. The open-source companies have refined the software model by selling subscriptions. They roll together support and maintenance and charge an annual fee, which is a healthy model, though not quite as wonderful as Microsoft's money-raking one. Tellingly, even Microsoft is casting an envious eye at aspects of the open-source business model. The company has been taking halting steps toward a similar subscription scheme for its software sales. Microsoft's subscription program, known as Soft ware Assurance, provides maintenance and support together with a software license. It lets you up grade to Microsoft's next version of the software for a predictable sum. But it also contains an implicit threat: If you don't switch to Software Assurance now, who knows how much Microsoft will charge you when you decide to upgrade? Chief information officers hate this kind of "assurance", since they're often perfectly happy running older versions of software that are proven and stable. Microsoft, on the other hand, rakes in the software-licensing fees only when customers upgrade. Software Assurance is Microsoft's attempt to get those same licensing fees but wrap them together with the service and support needed to keep systems running. That's why Microsoft finds the open-source model so threatening: open-source companies have no vested interest in getting more licensing fees and don't have to pad their service contracts with that extra cost. In the end, the main difference between open-source and proprietary software companies may be the size of the check you have to write.

单选题What kind of neutrinos would be most useful to astronomers?

单选题It seemed so promising—mirrors sprawled across desert land in the scorching southwest delivering clean electricity and helping Americans out of the increasing fuel crisis. Some scientists and industry developers claim that Nevada's empty and sun-drenched expanses alone could supply enough electricity to power the entire country. Now even the optimists fear this wonderful prospect may be a mirage. Congress cannot make up their mind to extend the tax-reducing bill for solar-energy projects, which solar advocates say is critical to the future of their industry but which is due to expire at the end of the year. The latest attempt failed in the Senate earlier this month, prospects for a deal before November's presidential and congressional elections now look dim. Uncertainty has led some investors to delay or abandon projects in the past few months. Rhone Resch, the president of the Solar Energy Industries Association, said if the tax-reducing bill is allowed to expire at the end of the year, "it will result in the loss of billions of dollars in new investments in solar. " Further dampening hopes for a big solar-energy boom, the federal Bureau of Land Management (BLM) has abruptly suspended new applications to put solar collectors on federal land. The agency says it has received more than 130 applications and needs to conduct a region-wide environmental impact study on the industry before it will accept any more. The study will take 22 months to complete, however. Few argue against trying to preserve precious water sources and protect desert tortoises and other creatures that might not enjoy cohabiting with sprawling fields of mirrors. But many solar advocates wonder why the government is not acting as cautiously when it comes to drilling for oil and gas. Senator Maria Cantwell, a Democrat from Washington State, wants a congressional probe into the proposed suspension. "The fact that the BLM pops this out without people even knowing about it, especially when solar thermal looks extremely promising as a power source, is not right," she says. Harry Reid of Nevada, who is the majority leader in the Senate, also condemns the BLM's freeze, saying that it could "slow new development to a crawl". The BLM is not without its supporters, however. At a public meeting on June 23rd in Golden, Colorado, Alex Daue, of the Wilderness Society, said that his organization supports renewable energy development as long as it doesn't damage other important resources. The message is clear: no rubber stamps, even for renewable energy.

单选题Men are generally better than women on tests of spatial ability, such as mentally rotating an object through three dimensions or finding their way around in a new environment. But a new study suggests that under some circumstances a woman's way of navigating is probably more efficient. Luis Pacheco-Cobos of the National Autonomous University of Mexico and his colleagues discovered this by following mushroom gatherers from a village in the state of Tlaxcala for two rainy seasons. Two researchers, each fitted with GPS navigation devices and heart-rate monitors, followed different gatherers on different days. They recorded the weight of the mushrooms each gatherer collected and where they visited. The GPS data allowed a map to be made of the routes taken and the heart-rate measurements provided an estimate of the amount of energy expended during their travels. The results, to be published in Evolution and Human Behavior, show that the men and women collected on average about the same weight of mushrooms. But the men travelled farther, climbed higher and used a lot more energy—70% more titan the women. The men did not move any faster, but they searched for spots with lots of mushrooms. The women made many more stops, apparently satisfied with, or perhaps belier at finding, patches of fewer mushrooms. Previous work has shown that men tend to navigate by creating mental maps of a territory and then imagining their position on the maps. Women are more likely to remember their mutes using landmarks. The study lends support to the idea that male and female navigational skills were honed differently by evolution for different tasks. Modern-day hunter-gatherers divide labor, so that men tend to do more hunting and women more gathering. It seems likely that early humans did much the same thing. The theory is that the male strategy is the most useful for hunting prey; chasing an antelope, say, would mean running a long way over a winding mute. But having killed his prey, the hunter would want to make a beeline for home rather than retrace his steps exactly. Women, by contrast, would be better off remembering landmarks and retracing the paths to the most productive patches of plants. The research suggests that in certain circumstances women are better at navigating than men, which might lend some comfort to a man desperately searching for an item in a supermarket while his exasperated wife methodically moves around the aisles filling the shopping trolley. He is simply not cut out for the job, evolutionarily speaking.

单选题It is not the thrill of winning, but the thrill of almost winning that sets a problem gambler apart from those who just fancy a flutter. A strong reaction in the brain in response to "near misses" is correlated with a greater tendency to compulsive gambling, according to new research. Gambling touches almost everyone, from friends playing online poker to grannies buying lotto tickets. For many it is just good fun, but for some it becomes a terrible addiction which wrecks lives: they need bigger wins to satisfy their craving, and when forced to stop they suffer withdrawal symptoms. Henry Chase of the University of Nottingham and Luke Clark of the University of Cambridge, are interested in the cognitive complexities of gamblers. For instance, gamblers often believe that games like roulette, or picking lottery numbers, involve some degree of skill, even though they do not. In games where skill does matter, such as football, a near miss like kicking a ball into the goalpost can rightly be associated with almost scoring a goal. So assigning value to an almost-goal makes some sense. But in games of chance, near misses are meaningless. They say nothing about the future likelihood of winning. Yet that is not the way many people think about it. Dr. Chase and Dr. Clark have found that in normal healthy volunteers, near misses that won participants not a penny still activated parts of the brain associated with monetary wins. In a new study in the Journal of Neuroscience they set out to discover just how that brain activation was related to gambling "severity". They invited 20 volunteers, two of whom were women, to play a kind of slot machine while a functional magnetic-resonance imaging scanner examined their brain activity. These machines show certain parts of the brain "lighting up" with increased blood flow as they become active. The volunteers all enjoyed some gambling, ranging from off-course betting on race horses and football matches to playing slot machines, scratch cards and lotteries. All but one volunteer—who had been abstinent for a year—gambled at least once a week. Bets ranged from five people who routinely spent ?10～100 ($15～150) a day on gambling and two who were willing to drop over ?10,000. Perhaps not surprisingly, 13 of the volunteers would have been considered to have an excessive gambling habit on conventional tests. The game was simple: when an icon on the left-hand reel lined up with the same icon on a right- hand one, the volunteer won a cash prize of 50 pence (75 cents). Sometimes the volunteers could pick the left-hand icon. At other times it was selected for them. A near miss came with the agonising deceleration of the right-hand reel so that something like a cowboy boot, an anchor or a banana eventually stopped within a space or two of lining up with a matching icon on the left. In fact, the results were manipulated and all participants got 30 wins, 60 near misses and 90 clear misses. The researchers found that those who scored highest in gambling severity also showed the most activity in the midbrain area in response to near misses. (They did not differ in their response to real wins, however.) This area of the brain is of interest to researchers because it is where dopamine, a neurotransmitter, is produced. Dopamine has been implicated in other addiction studies. It could be the near misses that enhance dopamine transmission in gamblers who suffer the most severe problems, the study suggests. Which means it might be possible to find treatments that reduce dopamine transmission in the brain to take some of the compulsion out of gambling.

单选题The willingness of doctors at several major medical centers to apologize .to patients for harmful errors is a promising step toward improving the rather disappointing quality of a medical system that kills tens of thousands of innocent patients a year inadvertently. For years, experts have lamented that medical malpractice litigation is an inefficient way to deter lethal or damaging medical errors. What they noticed, simply put it, is that most victims of malpractice never sue, and there is some evidence that many patients who do sue were not harmed by a physician"s error but instead suffered an adverse medical outcome that could not have been prevented. The details of what went wrong are often kept secret as part of a settlement agreement. What is needed, many specialists agree, is a system that quickly brings an error to light so that further errors can be headed off and that compensates victims promptly and fairly. Many doctors, unfortunately, have been afraid that admitting and describing their errors would only invite a costly lawsuit. Now, as described by Kevin Sack in The Times, a handful of prominent academic medical centers have adopted a new policy of promptly disclosing errors, offering earnest apologies and providing fair compensation. It appears to satisfy many patients, reduce legal costs and the litigation burden and, in some instances, helps reduce malpractice premiums. Here are some examples from colleges of the United States: at the University of Illinois, of 37 cases where the hospital acknowledged a preventable error and apologized, only one patient filed suit; at the University of Michigan Health System, existing claims and lawsuits dropped from 262 in August 2001 to 83 in August 2007, and legal costs fell by two-thirds. To encourage greater candor, more than 30 states have enacted laws making apologies for medical errors inadmissible in court. That sounds like a sensible step that should be adopted by other states or become federal law. Such laws could help bring more errors to light. Patients who have been harmed by negligent doctors can still sue for malpractice, using other evidence to make their case. Admitting errors is only the first step toward reforming the health care system so that far fewer mistakes are made. But reforms can be more effective if doctors are candid about how they went astray. Patients seem far less angry when they receive an. honest explanation, an apology and prompt, fair compensation for the harm they have suffered.

单选题The San Andreas fault is ______.

单选题{{B}}Text 1{{/B}} The Amazon River basin boasts the largest river system on Earth and harbors an ecosystem that is tremendously complex. Early travelers from renaissance Europe were overwhelmed by their first encounters. In 1531, Francisco Pizarro overthrew the Incan empire, removing the emperor from his throne and taking for Spain the Incan imperial treasures. A decade later his younger brother ventured east from the high plateau of the Andes Mountains in pursuit of the famous cities of gold and spices thought to be hidden in the jungle forest. Going down the river the expedition soon exhausted its supplies and a small group was sent ahead to search for food. Eight months later, this group emerged at the mouth of the Amazon, having made what would prove to be the first descent of the length of the river. A missionary who accompanied the group sent a remarkable account of their adventures to the Pope, including mention of the great signal drums that sounded from village to village far in advance of their arrival, warning of the coming of the European strangers. His manuscript records seeing innumerable settlements along the river—on one day they passed more than twenty villages in succession, and some of these are said to have stretched for six miles or more. Such reports have intrigued scientists ever since, for they describe dense populations and large federations of tribes which, if verified, would be entirely at odds with modern stereotypes of hidden, thinly scattered tribes scratching out an uncertain existence. Beginning in the late seventeenth-century, the successors to the first explorers recorded and collected many of the everyday objects fashioned from wood and other organic materials that usually rot in a tropical climate. Such collections housed in European museums preserve a "window" into cultures that were soon to experience huge changes brought about by foreign diseases and cruel abuse at the hands of Europeans. Population collapse and movement along the principal rivers of the Amazon system have contributed to a veil of misunderstanding that has long covered the cultural achievements of tropical forest societies. Diffuse bands hunting deep in the forest interior eventually came to be seen as the typical tropical forest adaptation. So much so that when archaeological studies began in earnest at the mouth of the Amazon in the 1950's, scientists argued that the sophisticated culture they were discovering could not have originated in the Amazon Basin itself, but must have been derived from more advanced cultures elsewhere. They imagined the tropical forest to be an "imitation paradise" unable to support much beyond a simple hunting-and-gathering way of life. This mistaken idea has exerted a persistent influence ever since.

单选题The purpose of the author in writing this text is

单选题Dr. Yoseph Bar-Cohen seems to suggest that

单选题 It was a ruling that had consumers seething with anger and many a free trader crying foul. On November 20th the European Court of Justice decided that Tesco, a British supermarket chain, should not be allowed to import jeans made by America's Levi Strauss from outside the European Union and sell them at cut-rate prices without getting permission first from the jeans maker. Ironically, the ruling is based on an EU trademark directive that was designed to protect local, not American, manufacturers from price dumping. The idea is that any brand-owning firm should be allowed to position its goods and segment its markets as it sees fit: Levi's jeans, just like Gucci handbags, must be allowed to be expensive. Levi Strauss persuaded the court that, by selling its jeans cheaply alongside soap powder and bananas, Tesco was destroying the image and so the value of its brands—which could only lead to less innovation and, in the long run, would reduce consumer choice. Consumer groups and Tesco say that Levi's case is specious. The supermarket argues that it was just arbitraging the price differential between Levi's jeans sold in America and Europe—a service performed a million times a day in financial markets, and one that has led to real benefits for consumers. Tesco has been selling some 15,000 pairs of Levi's jeans a week, for about half the price they command in specialist stores approved by Levi Strauss. Christine Cross, Tesco's head of global non-food sourcing, says the ruling risks "creating a Fortress Europe with a vengeance". The debate will rage on, and has implications well beyond casual clothes (Levi Strauss was joined in its lawsuit by Zino Davidoff, a perfume maker). The question at its heart is not whether brands need to control how they are sold to protect their image, but whether it is the job of the courts to help them do this. Gucci, an Italian clothes label whose image was being destroyed by loose licensing and over-exposure in discount stores, saved itself not by resorting to the courts but by ending contracts with third-party suppliers, controlling its distribution better and opening its own stores. It is now hard to find cut-price Gucci anywhere. Brand experts argue that Levi Strauss, which has been losing market share to hipper rivals such as Diesel, is no longer strong enough to command premium prices. Left to market forces, so-so brands such as Levi's might well. fade away and be replaced by fresher labels. With the courts protecting its prices, Levi Strauss may hang on for longer. But no court can help to make it a great brand again.

单选题Over the past century, all kinds of unfairness and discrimination have been condemned or made illegal. But one insidious form continues to thrive: alphabetism. This, for those as yet unaware of such a disadvantage, refers to discrimination against those whose surnames begin with a letter in the lower half of the alphabet. It has long been known that a taxi firm called AAAA cars has a big advantage over Zodiac cars when customers thumb through their phone directories. Less well known is the advantage that Adam Abbott has in life over Zo ? Zysman. English names are fairly evenly spread between the halves of the alphabet. Yet a suspiciously large number of top people have surnames beginning with letters between A and K. Thus the American president and vice-president have surnames starting with B and C respectively; and 26 of George Bush"s predecessors (including his father) had surnames in the first half of the alphabet against just 16 in the second half. Even more striking, six of the seven heads of government of the G7 rich countries are alphabetically advantaged (Berlusconi, Blair, Bush, Chirac, Chré tien and Koizumi). The world"s three top central bankers (Greenspan, Duisenberg and Hayami) are all close to the top of the alphabet, even if one of them really uses Japanese characters. As are the world"s five richest men (Gates, Buffett, Allen, Ellison and Albrecht). Can this merely be coincidence? One theory, dreamt up in all the spare time enjoyed by the alphabetically disadvantaged, is that the rot sets in early. At the start of the first year in infant school, teachers seat pupils alphabetically from the front, to make it easier to remember their names. So short-sighted Zysman junior gets stuck in the back row, and is rarely asked the improving questions posed by those insensitive teachers. At the time the alphabetically disadvantaged may think they have had a lucky escape. Yet the result may be worse qualifications, because they get less individual attention, as well as less confidence in speaking publicly. The humiliation continues. At university graduation ceremonies, the ABCs proudly get their awards first; by the time they reach the Zysmans most people are literally having a ZZZ . Shortlists for job interviews, election ballot papers, lists of conference speakers and attendees: all tend to be drawn up alphabetically, and their recipients lose interest as they plough through them.

单选题{{B}}Text 2{{/B}} Sleep is a funny thing. We' re taught that we should get seven or eight hours a night, but a lot of us get by just fine on less, and some of us actually sleep too much. A study out of the University of Buffalo last month reported that people who routinely sleep more than eight hours a day and are still tired are nearly three times as likely to die of stroke—probably as a result of an underlying disorder that keeps them from snoozing soundly. Doctors have their own special sleep problems. Residents are famously sleep deprived. When I was training to become a doctor, it was not unusual to work 40 hours in a row without rest. Most of us took it in stride, confident we could still deliver the highest quality of medical care. Maybe we shouldn't have been so sure of ourselves. An article in the Journal of the American Medical Association points out that in the morning after 24 hours of sleeplessness, a person' s motor performance is comparable to that of someone who is legally intoxicated. Curiously, surgeons who believe that operating under the influence is grounds for dismissal often don't think twice about operating without enough sleep. "I could tell you horror stories, ' says Jaya Agrawal, president of the American Medical Student Association, which runs a website where residents can post anonymous anecdotes. Some are terrifying. "I was operating after being up for over 36 hours," one writes. "I literally fell asleep standing up and nearly face planted into the wound." "Practically every surgical resident I know has fallen asleep at the wheel driving home from work, "writes another. "I know of three who have hit parked cars. Another hit a convenience store on the roadside, going [1051an/h]." "Your own patients have become the enemy," writes a third," because they are the one thing that stands between you and a few hours of sleep." Agrawal' s organization is supporting the Patient and Physician Safety and Protection Act of 2001, introduced last November by Representative John Conyers Jr. of Michigan. Its key provisions, modeled on New York State' s regulations, include an 80-hour workweek and a 24hour work-shift limit. Most doctors, however, resist such interference. Dr. Charles Binkley, a senior surgery resident at the University of Michigan, agrees that something needs to be done but believes" doctors should be bound by their conscience, not by the government." The U. S. controls the hours of pilots and truck drivers. But until such a system is in place for doctors, patients are on their own. If you're worried about the people treating you, you should feel free to ask how many hours of sleep they have had. Doctors, for their part, have to give up their pose of infallibility and get the rest they need.