单选题 HOW soon your performance will be rated may influence how well you do, according to a new study published in the journal Psychological Science. In the study, researchers Keri L. Kettle and Gerald Hubl from the University of Alberta set out to determine whether the timing of feedback influences performance. Because earlier feedback means a more proximate possibility of disappointment, the researchers hypothesized that students told they would be learning their grade sooner would be more likely to perform well, compared with those who wouldn't fend out their grade until later. Of 501 students taking a particular course, 271 agreed to participate in the study. All students were assigned a four minute oral presentation, which they had to deliver in front of about 10 classmates. Their performance was ranked on a scale of 1-10 by classmates, and the average of those scores made up their grade for the assignment. Prior to giving their oral presentation, study participants were asked to predict how well they would do, and were also told how soon they would learn their grade. The researchers found that study participants who'd been told they would be given their scores earlier performed far better than those told they'd receive their scores later. What's more, despite the fact that, on average, students who anticipated fending out how they'd done earlier significantly outperformed classmates who were given their scores later, they were more likely to predict low marks for themselves. In contrast, those who were told they wouldn't learn their scores until later were more likely to predict very high marks-which they seldom actually went on to earn. As a control, the researchers also assessed the scores of the 230 students who had declined to participate in the study. While students with the earliest feedback scored in the 60th percentile on average, and those with the latest feedback scored in the 40th percentile on average, those not included in the study (and whose feedback time hadn't been manipulated) consistently scored in the 50th percentile. The findings suggest that "mere anticipation of more rapid feedback improves performance," the authors conclude, and that, interestingly, proximity of feedback influences predicted performance and actual performance differently. As the authors sum up: "People do best precisely when their predictions about their own performance are least optimistic." The influence of feedback anticipation on performance has implications beyond the classroom as well, the researchers argue-in the way that managers respond to employee work, for example, or maybe even how Mom and Dad size up how clean that room is. The findings, Kettle and Hubl conclude, "have important practical implications for all individuals who are responsible for mentoring and for evaluating the performance of others."

单选题By using the word "correlates" (Line 7, Paragraph 3 ), the author implies that

单选题 A child who has once been pleased with a tale likes, as a rule, to have it retold in identically the same words, but this should not lead parents to treat printed fairy stories as sacred texts. It is always much better to tell a story than read it out of a book, and, if a parent can produce what, in the actual circumstances of the time and the individual child, is an improvement on the printed text, so much the better. A charge made against fairy tales is that they harm the child by frightening him or arousing his sadistic impulses. To prove the latter, one would have to show in a controlled experiment that children who have read fairy stories were more often guilty of cruelty than those who had not. Aggressive, destructive, sadistic impulses every child has and, on the whole, their symbolic verbal discharge seen is to be rather a safety valve than an incitement to overt action. As to fears, there are, I think, well-authenticated cases of children being dangerously terrified by some fairy stories. Often, however, this arises from the child having heard the story once. Familiarity. with the story by repetition turns the pain of fear into the pleasure of the fear faced and mastered. There are also people who object to fairy stories on the grounds that they are not objectively true, that giants, witches, two -headed dragons, magic carpets, etc., do not exist; and that, instead of indulging his fantasies in fairy tales, the child should be taught how to adapt to reality by studying history and mechanics. I find such people, I must confess, so unsympathetic and peculiar that I do not know how to argue with them. If their case were sound, the world should be full of mad men attempting to fly from New York to Philadelphia on a broomstick or covering a telephone with kisses in the belief that it was their enchanted girl-friend. No fairy story ever claimed to be a description of the external world and no sane child has ever believed that it was.

单选题Invention and innovation have been quintessentially American pursuits from the earliest days of the republic. Benjamin Franklin was a world-famous scientist and inventor. Cyrus McCormick and his harvester, Samuel F. B. Morse and the telegraph, Alexander Graham Bell and the telephone—the 19th century produced a string of inventors and their world-changing creations. And then there was the greatest of them all, Thomas Alva Edison. He came up with the crucial devices that would give birth to three enduring American industries:electrical power, recorded music and motion pictures. Much of the world we live in today is a legacy of Edison and of his devotion to science and innovation. Edison taught us to invent, and for decades we were the best in the world. But today, more than 160 years after Edison"s birth, America is losing its scientific edge. A landmark report released in May by the National Science Board lays out the numbers:while U. S. investment in R&D as a share of total GDP has remained relatively constant since the mid-1980s at 2.7% , the federal share of R&D has been consistently declining—even as Asian nations like Japan and South Korea have rapidly increased that ratio. At the same time, American students seem to be losing interest in science. Only about one-third of U. S. bachelor"s degrees are in science or engineering now, compared with 63% in Japan and 53% in China. It"s ironic that nowhere is America"s position in science and technology more threatened than in the industry that Edison essentially invented: energy. Clean power could be to the 21st century what aeronautics and the computer were to the 20th, but the U. S. is already falling behind. Meanwhile, Congress remains largely paralyzed . Though in May the House of Representatives was finally able to pass the $ 86 billion America Competes Reauthorization Act, which would double the budgets of the National Science Foundation (NSF) and Energy Department"s Office of Science, the bill"s fate is cloudy in the deadlocked Senate. "At this rate... we"ll be buying most of our wind generators and photovoltaic panels from other countries, " former NSF head Arden L. Bement said at a congressional hearing recently. "That"s what keeps me awake sometimes at night. " Some erosion of the U. S. "s scientific dominance is inevitable in a globalized world and might not even be a bad thing. Tomorrow"s innovators could arise in Shanghai or Seoul or Bangalore. And Edison would counsel against panic—as he put it once, " Whatever setbacks America has encountered, it has always emerged as a stronger and more prosperous nation. " But the U. S. will inevitably decline unless we invest in the education and research necessary to maintain the American edge . The next generation of Edisons could be waiting. But unless we move quickly, they won"t have the tools they need to thrive .

单选题A factory that makes uranium fuel for nuclear reactors had a spill so bad it kept the plant closed for seven months last year and became one of only three events in all of 2006 serious enough for the Nuclear Regulatory Commission to include in an annual report to Congress. After an investigation, the commission changed the terms of the factory's license and said the public had 20 days to request a hearing on the changes. But no member of the public ever did. In fact, no member of the public could find out about the changes. The document describing them, including the notice of hearing rights for anyone who felt adversely affected, was stamped "official use only," meaning that it was not publicly accessible. The agency would not even have told Congress which factory was involved were it not for the efforts of Gregory B. Jaczko, one of the five commissioners. Mr. Jaczko identified the company, Nuclear Fuel Services of Erwin, Tenn. , in a memorandum that became part of the public record. His memorandum said other public documents would allow an informed person to deduce that the factory belonged to Nuclear Fuel Services. Such secrecy by the Nuclear Regulatory Commission is now coming under attack by influential members of Congress. These lawmakers argue that the agency is withholding numerous documents about nuclear facilities in the name of national security, but that many withheld documents are not sensitive. The lawmakers say the agency must rebalance its penchant for secrecy with the public's right to participate in the licensing process and its right to know about potential hazards. The agency, the congressmen said, " has removed hundreds of innocuous documents relating to the N. F. S. plant from public view. " With a resurgence of nuclear plant construction expected after a 30-year hiatus, agency officials say frequently that they are trying to strike a balance between winning public confidence by regulating openly and protecting sensitive information. A commission spokesman, Scott Burnell, said the "official use only" designation was under review. As laid out by the commission's report to Congress and other sources, the event at the Nuclear Fuel Service factory was discovered when a supervisor saw a yellow liquid dribbling under a door and into a hallway. Workers had previously described a yellow liquid in a "glove box," a sealed container with gloves built into the sides to allow a technician to manipulate objects inside, but managers had decided it was ordinary uranium. In fact, it was highly enriched uranium that had been declared surplus from the weapons inventory of the Energy Department and sent to the plant to be diluted to a strength appropriate for a civilian reactor. If the material had gone critical, "it is likely that at least one worker would have received an exposure high enough to cause acute health effects or death," the commission said. Generally, the Nuclear Regulatory Commission does describe nuclear incidents and changes in licenses. But in 2004, according to the committee's letter, the Office of Naval Reactors, part of the Energy Department, reached an agreement with the commission that any correspondence with Nuclear Fuel Services would be marked "official use only. /

单选题The text specially states that

单选题The discovery of the ship is important to students of early ships and their routes because ______.

单选题AnthropologistshavelongspeculatedthatearlyhumansmayhavematedwithNeanderthals,butthelateststudyprovidesthestrongestevidencesofar,suggestingthatsuchencounterstookplacearound60,000yearsagointheMiddleEast.Small,pioneeringgroupsofmodernhumansbegantoleaveAfrica80,000yearsagoandreachedlandoccupiedbytheNeanderthalsastheyspreadintoEurasia.ThetwomayhavelivedalongsideeachotherinsmallgroupsuntiltheNeanderthalsdiedout30,000yearsago.ScientistsledbySvantetookfouryearstosequencethewholeNeanderthalgenomefrompowderedbonefragmentstakenfromthreefemaleswholivedinEurope40,000yearsago.ToseehowsimilartheNeanderthalwastomodernhumans,theteamcomparedtheancientDNAwiththegenomesoffivepeoplefromFrance,China,southernAfrica,westernAfricaandPapuaNewGuinea.Thestudyisthefirsttoattemptawhole-genomecomparisonbetweenNeanderthalsandmodernhumans.TheresearchersfoundthatmodernhumansandNeanderthalsshared99.7%oftheirDNA,whichwasinheritedfromacommonancestor400,000yearsago.FurtheranalysisrevealedthatNeanderthalsweremorecloselyrelatedtomodernhumanswholeftAfricathantothedescendantsofthosewhostayed.Between1%and4%oftheDNAinmodernEuropeans,AsiansandthoseasfarafieldasPapuaNewGuinea,wasinheritedfromNeanderthals."ThoseofuswholiveoutsideAfricacarryalittleNeanderthalinus,"saidProfessor"NeanderthalsprobablymixedwithearlymodernhumansbeforeHomosapienssplitintodifferentgroupsinEuropeandAsia.Thecomparisonofthesetwogeneticsequencesenablesustofindoutwhereourgenomediffersfromthatofourclosestrelative."InterbreedingbetweenhumansandNeanderthalsmaynonethelesshavebeenrare.JusttwoNeanderthalfemalesinagroupofaroundahundredhumanswouldhavebeenenoughtoleavesuchatraceinourgenome,providedthatwasthegroupthatgaverisetoallmodernhumansoutsideAfrica.ThestudywasgreetedbyscientistsasalmostcertainconfirmationthatmodernhumansandNeanderthalsmatedwhenthegroupscrossedpaths."Itcertainlytellsussomethingabouthumannature,"saidChrisStringer,headofhumanoriginsattheNaturalHistoryMuseuminLondon.EdGreen,aseniorauthoronthestudysaid:"Howthesepeopleswouldhaveinteractedculturallyisnotsomethingwecanspeculateoninanymeaningfulway.Butknowingthattherewasgeneflowisimportant,anditisfascinatingtothinkabouthowthatmayhavehappened."

单选题The author quoted the studies of teachers' reading to show that

单选题{{B}}Text 4{{/B}} Everyday some 16m barrels of oil leave the Gulf through the Strait of Hormuz. That is enough to fill a soft-drink can for everyone on earth, or to power every motor vehicle on the planet for 25 miles (40kin). Gulf oil accounts for 40% of global trade in the sticky stuff. More important, it makes up two-thirds of known deposits. Whereas at present production rates the rest of the world's oil reserves will last for a mere 25 years, the Gulf's will last for 100. In other words, the region's strategic importance is set to grow and grow. Or at least so goes the conventional wisdom, which is usually rounded out with scary talk of unstable supplies, spendthrift regimes and a potential fundamentalist menace. Yet all those numbers come with caveats. A great deal of oil is consumed by the countries that produce it rather than traded, so in reality the Gulf accounts for less than a quarter of the world's daily consumption. As for reserves, {{U}}the figures are as changeable as a mirage in the desert{{/U}}. The most comprehensive research available, conducted by the US Geological Survey, refers to an "expected" total volume for global hydrocarbon deposits that is about double current known reserves. Using that figure, and throwing in natural gas along with oil, it appears that the Gulf contains a more moderate 30% or so of the planet's future fossil-fuel supplies. Leaving out the two Gulf states that are not covered in this survey--Iran and Iraq--the remaining six between them hold something like 20% of world hydrocarbon reserves, not much more than Russia. All the same, {{U}}it is still a hefty chunk{{/U}}; enough, you might think, to keep the people living atop the wells in comfort for the foreseeable future. But you might be wrong. At present, the nations of the Gulf Cooperation Council have a combined national income roughly equal to Switzerland's, but a population which, at around 30m, is more than four times as big. It is also the fastest-growing on earth, having increased at nine times the Swiss rate over the past quarter-century. Meanwhile the region's share of world oil trade has fallen, as has the average price per barrel. As a result, the income per person generated by GCC oil exports has been diminishing since the 1970s. True, surging demand from America and Asia has recently boosted the Gulf's share of trade, but the medium-term outlook for oil pries remains weak. Combined with continued growth in oil consumption, this should create sustained upward pressure on prices. And high oil prices will speed the search for alternatives. Who knows, in 20 years' time fuel cells and hydrogen power may have started to become commercial propositions.

单选题In a new list of the most powerful gay men and women in the country, out magazine has lots of household names at the top. But high among the rich and famous is Tim Gill. Huh? Who is he, and why is he ranked as the fourth most powerful gay person in the country? Gill is a 53-year-old snowboarder, retired computer programmer and multimillionaire. He made his fortune by founding Quark, the pioneering desktop publishing software company. After selling the firm, he started the Gill Foundation, which has invested $110 million nationwide in gay causes over the past decade. The Gill Action Fund threw $15 million into a dozen states during the 2006 midterm elections, targeting 70 politicians regarded as unhelpful to gay causes: 50 went down. And the fund is helping transform the political face of Colorado. In 2004, Gill's money helped send Democrat Ken Salazar to the U.S. Senate. His dollars have also helped put Democrats in control of the Colorado legislature for the fast time in four decades. That could have an impact on the fate of the Two Parent Adoption Bill, currently being considered by Colorado legislators, which would allow gay couples to adopt. The proposal was rejected twice before, but that was before the statehouse switched from red to blue. Now Colorado Democrats have passed the bill in the House and expect it to pass the Senate. Impatient with the lack of gay rights progress this past decade, Gill is pushing hard to end injustice and inequality by the end of the next decade. And recognizing that most anti-gay initiatives are born at the state level, Gill has developed a national political strategy based on successes in Colorado. They've taken an in-state model and applied it to the entire country. Gill and his people are incredibly strategic. They put their funding where they can take control of legislatures. They're putting them brilliantly in legislative environments where a few seats changing will change the entire control of a state. While Gill has recently opened a Washington office, his representatives, in keeping with past strategy, insist that no individual political targets have yet been chosen for 2008. Another formidable element of Gill's power is his network of deep-pocketed allies in the mountain states. An hour south of Laramie, in Ft. Collins, lives medical equipment heiress Pat Stryker, who is, along with Gill (Actually Stryker is a billionaire; her brother Jon is gay and both give generously to gay causes.) What he has are extremely wealthy individuals who aren't personally interested in running for anything but have this tremendous passion. Tim Gill is actually changing the political landscape.

单选题{{B}}Text 4{{/B}} LAST month, America's National Law Journal told its readers that "employment lawyers are warning lovestruck co-workers to take precautions in the office before locking lips outside". The advice came too late for Harry Stonecipher. The boss of Boeing was forced to resign last weekend—for reasons that will strike many outsiders as absurd—after his board were told of an affair that the 68-year-old married man had been conducting with a female employee "who did not report directly to him". Inevitably, as the week rolled on, details of the affair rolled out. The other party was reported to be Debra Peabody, who is unmarried and has worked for Boeing for 25 years. The couple were said to have first got together at Boeing's annual retreat at Palm Desert, California in January. After that much of the affair must have been conducted from a distance: Mr. Stonecipher's office is at Boeing's headquarters in Chicago; Ms Peabody runs the firm's government-relations office in Washington, DC. They exchanged e-mails, it seems, as office lovers tend to do these days, and therein probably lay Mr Stonecipher's downfall. Lewis Platt, Boeing's chairman, said that Mr Stonecipher broke a company rule that says: "Employees will not engage in conduct or activity that may raise questions as to the company's honesty, impartiality, reputation or otherwise cause embarrassment to the company." Having an affair with a fellow employee is not, of itself, against company rules; causing embarrassment to Boeing is. It seems that the board judged that the contents of the lovers' e-mails would have been bad for Boeing had they been made public. Gone are the days when a board considered such matters none of its business, as Citibank's did in 1991 when its boss, John Reed, became the talk of Wall Street for having an affair with a stewardess on Citi's corporate jet. At Boeing, a whistleblower is said to have forwarded the messages to Mr Platt. In general, e-mails are encrypted and not accessible to anyone who does not know the sender's password. But many firms install software designed to search electronic communications for key words such as, "sex" and "CEO". A study last year of 840 American firms by the American Management Association found that 60% of them check external e-mails (incoming and outgoing), while 27% scrutinize internal messages between employees. Sweet nothings whispered by the water cooler may travel less far these days than electronic billets doux. Boeing is particularly sensitive to embarrassment at the moment. Mr. Stonecipher was recalled from retirement only 15 months ago, after the company's previous boss, Phil Condit, and its chief financial officer, Michael Sears, had left in the wake of a scandal involving an illegal job offer to a Pentagon official. Mr Stonecipher, a crusty former number two at Boeing, was brought back specifically to raise the company's ethical standards and to help it be seen in its main (and affectedly puritanical) market, in Washington, DC, as squeaky clean. Verbally explicit extra-marital affairs are inconsistent with such a strategy, it seems, though they are not yet enough to bring down future kings of England. In corporate life, such affairs are hardly unusual. One survey found that one-quarter of all long-term relationships start at work; another found that over 40% of executives say they have been involved in an affair with a colleague, and that in half of these cases one or other party was married at the time. Many a boss has married his assistant and lived happily ever after. Boeing apparently used to accept this: Mr. Condit's fourth wife was a colleague before they married.

单选题According to the author, user-led innovation

单选题Time spent in a bookshop can be most enjoyable, whether you are a book-lover or merely there to buy a book as a present. You may even have entered the shop just to find shelter from a sudden shower. But the desire to pick up a book with an attractive dust-jacket is irresistible. You soon become absorbed in some book or other, and usually it is only much later that you realize that you have spent far too much time there. This opportunity to escape the realities of everyday life is, I think, the main attraction of a bookshop. There are not many places where it is possible to do this. A music shop is very much like a bookshop. You can wander round such places to your heart's content. If it is a good shop, no assistant will approach you with the inevitable greeting: "Can I help you, sir?" You needn't buy anything you don't want. In a bookshop an assistant should remain in the background until you have finished browsing. Then, and only then, are his services necessary. You have to be careful not to be attracted by the variety of books in a bookshop. It is very easy to enter the shop looking for a book on, say, ancient coins and to come out carrying a copy of the latest best-selling novel and perhaps a book about brass-rubbing- something which had only vaguely interested you up till then. This volume on the subject, however, happened to be so well illustrated and the part of the text you read proved so interesting that you just had to buy it. This sort of thing can be very dangerous. Booksellers must be both long suffering and indulgent. There is a story which well illustrates this. A medical student had to read a textbook which was far too expensive for him to buy. He couldn't obtain it from the library and the only copy he could find was in his bookshop. Every afternoon, therefore, he would go along to the shop and read a little of the book at a time. One day, however, he was dismayed to find the book missing from its usual place and about to leave when he noticed the owner of the shop beckoning to him. Expecting to be reproached, he went toward him. To his surprise, the owner pointed to the book, which was tucked away in a corner. "I put it there in case anyone was tempted to buy it," he said, and left the delighted student to continue his reading.Notes: to one's heart's content尽情地。 beckon v. 打招呼。

单选题It's often hard to see your mistakes as you're making them. "Yikes! The kids are moving back in!" Thus goes the moan of the baby boom generation, around 2007. But letting the kids move back in is not the social error we're talking about. Instead, the big mistake is the loudly voiced annoyance of the boomers. Most mistakenly decry the notion of the boomerang generation. For example, the authors of a recent book on the topic, Morn, Can 1 Move Back In With You? report, "The parents of the 39 million twenty-somethings in the United States face the unprecedented challenge of their children's prolonged adolescence. " The subtitle of the book is even more revealing: "A survival guide for parents of twenty-somethings. " In order to fully appreciate the depth of the error being made here, we all need to step back a bit and look at the bigger picture. This epidemic of kids moving back home is first not "unprecedented," and second, it's not a bad thing. The precedent for this trend can be found among the other 6.2 billion non-Americans on the planet, many of whom happily live with their adult children, often in three-generation households. Finally, the agrarian history of this country before World War II allowed kids to live and work around the farm well into adulthood. Adult kids moving back home is merely the most noticeable symptom of a larger, fundamental transformation of American society. We are nationally beginning to recognize the costs of the independence the so-called greatest generation imposed on us. Kids in their generation went off to World War II and grew up on the bloody beaches of distant lands. After the war, the survivors had factories to build and the wealth to buy their white-picket-fence dreams out West. They designed a social and fiscal system that has served their retirement years very well. But their historically unique retirement system mistakenly celebrated independence and ignored the natural state of human beings -that is, interdependence. Moreover, their system breaks down with the onslaught of their kids' retirement. Regarding boomerang kids, most demographers focus on the immediate explanations for the changes, such as the growing immigrant population, housing shortages and high prices, and out-of-wedlock childbearing. Many psychologists have noted that baby-boomer parents enjoy closer relationships with their fewer children that allow extended cohabitation. However, all these explanations are simply symptoms of the larger, more fundamental reuniting of Americans into households. The rate at which our American culture is adapting will accelerate as baby boomers begin retiring. Creative housing arrangements are necessitating and allowing three generations to live together again. But such multigenerational households don't make sense for everyone. The culture itself frequently gets in the way, reinforcing the perception of a stigma attaching to lack of independence. Despite these problems, once you begin talking with your friends about three-generation households, you will begin hearing stories about how such obstacles are being overcome.

单选题By mentioning "the doping affair in the Tour de France", the author is talking about