单选题{{B}}Text 3{{/B}} Although many factors affect human health during periods in space, weightlessness is the dominant and single most important one. The direct and indirect effects of weightlessness lead to a series of related responses. Ultimately, the whole body, from bones to brain, kidneys to bowels, reacts. When space travelers grasp the wall of their spacecraft and jerk their bodies back and forth, they say it feels as though they are stationary and the spacecraft is moving. The reason is based in our reliance on gravity to perceive our surroundings. The continuous and universal nature of gravity removes it from our daily notice, but our bodies never forget. Whether we realize it or not, we have evolved a large number of silent, automatic reactions to cope with the constant stress of living in a downward-pulling world. Only when we decrease or increase the effective force of gravity on our bodies do our minds perceive it. Our senses provide accurate information about the location of our center of mass and the relative positions of our body parts. Our brains integrate signals from our eyes and ears with other information from the organs in our inner ear, from our muscles and joints, and from our senses of touch and pressure. The apparatus of the inner ear is partitioned into two distinct components: circular, fluid-filled tubes that sense the angle of the head, and two bags filled with calcium crystals embedded in a thick fluid, which respond to linear movement. The movement of the calcium crystals sends a signal to the brain to tell us the direction of gravity. This is not the only cue the brain receives. Nerves in the muscles, joints, and skin—particularly the slain on the bottom of the feet—respond to the weight of limb segments and other body parts. Removing gravity transforms these signals. The inner ear no longer perceives a downward tendency when the head moves. The limbs no longer have weight, so muscles are no longer required to contract and relax in the usual way to maintain posture and bring about movement. Nerves that respond to touch and pressure in the feet and ankles no longer signal the direction of down. These and other changes contribute to orientation illusions, such as a feeling that the body or the spacecraft spontaneously changes direction. In 1961 a Russian astronaut reported vivid sensations of being upside down; one space shuttle specialist in astronomy said, "When the main engines cut off, I immediately felt as though we had inverted 180 degrees." Such illusions can recur even after some time in space.

单选题You could say on the court, these are the best days in the history of NBA. So why isn't the world is singing the praise of the NBA? Why isn't today's NBA outperforming the NFL, NASCAR, and Major League of Baseball (MLB), all of which have been rocked by scandals large and small over the last few years? Simple Because today's NBA scares the white people. The NBA stands at the dead-center intersection of two rampant social dynamics: the ascendancy of hip-hop culture and 21st-centrury marketing's sworn duty to easily definable demographic group. Break yourself into generalized demographic qualities: gender, age, race, economic class. There is full range of music, TV shows, movies, and website explicitly designed to keep you warm and toasty in your comfort zone, free from sharp edges. The NBA as it stands today has plenty of sharp edges and has a serious image problem; more than any other sports. For years, whites make up a majority of fan base, blacks make up a majority of players. And those players have benefited from ever-upward-spiraling paychecks, they've exercised their influence' to shape the sight of the game around them in their own image. But the NBA is still all about improvisation, artistry, jazz, poetry on the way to and above the rim. And while we appreciated the artistry in and of itself, the fact that we can't do it puts many fans at some kind small, but measurable emotional distance from the game. For the white audience, the skill divide one thing. There always been players that could do things the rest of us couldn't. What's freaking white Americans out is the way NBA is embracing every element' of hip-hop culture--the music, the fashion, the attitude, everything... Many events, stories hurt NBA, cementing its lawless-blacks image in observers' minds. Referring to the word "thug", that's operative in short-handing the new NBA culture, as many observers noted. "Thug" was so-opted by black culture sometime during the Tupac Era. When people slag NBA' players as "thug", it's good bet they're not taking about Adam Morris or J. J. Redic. It's absolutely a racial tag. The NBA, more than any other sports entity, has potential to be a bridge between cultures, a way to bring both sides together in cheering some best athletes of any color. It's already produced Jordan, the most widely known athlete in history, and it's gaining ground fast on soccer as the world's best known sport. But it's fragile indeed, with fans in colors viewing basketball as a zero-sum game, where every stereotypically black or white culture apparently forces out it's ethic opposite. But with serious image problems, another slat falls out of the bridge. And it's not hard to imagine a time when nobody will be interested in crossing over.

单选题Baby boomers fretting over their pensions should spare a thought for Constance DeCherney. Like many of her generation, the 27-year-old Web strategist at Planned Parenthood in New York has done little to prepare for retirement. "Just the idea of [saving for retirement] feels overwhelming," she says. "My fear of doing something wrong, or not doing enough, sort of paralyzes me." DeCherney is typical of America's so-called Generation Y, the twentysomethings who have entered the workforce in the past I0 years. Already saddled with student debts averaging almost $20,000, according to New York-based think tank Demos, Gen Y is in a tougher financial position than previous generations. The average salary for 25-to 34-year- olds, for instance, fell 19 percent over the last 30 years, after adjusting for inflation, to $35,100, Demos estimates. That's if they can get jobs: unemployment among 19-to 24-year- olds stands at 15.3 percent vs. the overall rate of 9.5 percent, according to the Bureau of Labor Statistics. While many of their parents have guaranteed retirement income from being in a company-funded pension for part of their careers, Gen Y is "the first do-it-yourself retirement generation," says Catherine Collinson, president of the Transamerica Center for Retirement Studies in Los Angeles. Investment companies are stepping up efforts to engage Gen Yers in retirement planning. Charles Schwab has revamped its website to include weekly advice for younger workers on everything from retirement planning to paying down debt. Vanguard is testing out social media, using more blogs, a Facebook page, and soon, Twitter. "It's how this younger generation learns," says Vanguard Chief Executive Officer William McNabb Ⅲ. Fidelity, the nation's largest 401 (k) administrator, in June launched an iPhone app for tracking retirement savings and has replaced bulky pension literature with e-mail updates. "This generation lacks confidence about making financial decisions," says Beth McHugh, Fidelity's vice-president of market insights. "You have to explain why planning for retirement is so important." That's presuming you can get their attention. Fewer than 4,000 Facebook users have clicked the "like" button for Fidelity's page and about 9,000 have done so for Vanguard's. Meanwhile, 4.2 million people say they like Apple iTunes on Facebook. Schwab, which began sending Twitter feeds in mid-June, has 277 followers. Whole Foods Market has 1.8 million. Some baby boomer parents enlist the help of their financial planners in giving their kids a retirement reality check. Jim Stoops, a Schwab financial consultant in Chicago, says his 250-plus clients often bring their sons and daughters to his office for advice. "Parents just can't believe how difficult retirement will be for their children," he says. "They're trying to instill financial values in their kids./

单选题It can be learned from the last paragraph that the Phase Three program contained

单选题About the computer towns and the computer clubs, David Tebutte thinks that______

单选题Mark Twain once observed that giving up smoking is easy. He knew, because he'd done it hundreds of times himself. Giving up for ever is a trifle more difficult, apparently, and it is well known that it is much more difficult for some people than for others. Why is this so? Few doctors believe any longer that it is simply a question of will power. And for those people that continue to view addicts as merely "weak", recent genetic research may force a rethink. A study conducted by Jacqueline Vink, of the Free University of Amsterdam, used a database called the Netherlands Twin Register to analyze the smoking habits of twins. Her results, published in the Pharmacogenomics Journal, suggest that an individual's degree of nicotine dependence, and even the number of cigarettes he smokes per day, are strongly genetically influenced. The Netherlands Twin Register is a voluntary database that contains details of some 7,000 pairs of adult twins (aged between 15 and 70 ) and 28,000 pairs of childhood twins. Such databases are prized by geneticists because they allow the comparison of identical twins (who share all their genes) with fraternal twins (who share half). In this case, however, Dr. Vink did not make use of that fact. For her, the database was merely a convenient repository of information. Instead of comparing identical and fraternal twins, she concentrated on the adult fraternal twins, most of whom had completed questionnaires about their habits, including smoking, and 536 of whom had given DNA samples to the register. The human genome is huge. It consists of billions of DNA "letters", some of which can be strung together to make sense (the genes) but many of which have either no function, or an unknown function. To follow what is going on, geneticists rely on markers they have identified within the genome. These are places where the genetic letters may vary between individuals. If a particular variant is routinely associated with a particular physical feature or a behavior pattern, it suggests that a particular version of a nearby gene is influencing that feature or behavior. Dr. Vink found four markers which seemed to be associated with smoking. They were on chromosomes 3, 6, 10 and 14, suggesting that at least four genes are involved. Dr. Vink hopes that finding genes responsible for nicotine dependence will make it possible to identify the causes of such dependence. That will help to classify smokers better (some are social smokers while others are physically addicted) and thus enable "quitting" programs to be customized. Results such as Dr. Vink' s must be interpreted with care. Association studies, as such projects are known, have a disturbing habit of disappearing, as it were, in a puff of smoke when someone tries to replicate them. But if Dr. Vink really has exposed a genetic link with addiction, then Mark Twain's problem may eventually become a thing of the past.

单选题What the author wants to suggest may be best interpreted as

单选题Aristotle believed that the heavens were perfect. If they ever were, they are no longer. The skies above Earth are now littered with the debris (残骸) of dead satellites, bits of old rockets and the odd tool dropped by a spacewalking astronaut. Such is the extent of the detritus that the first accidental collision between two satellites has already taken place. It happened in February 2009, when a defunct (废弃的) Russian Cosmos smashed into a functioning American Iridium, destroying both and creating even more space junk. To stop this sort of thing happening again Vaios Lappas of the University of Surrey, in England, has designed a system that will remove satellites from orbit at the end of their useful lives--and as a bonus will scour part of the sky clean as it does so. Dr. Lappas's satellite-removal system employs a solar sail. As light from the sun hits the sail, it imparts a minuscule but continuous acceleration. When a satellite is first launched, the sail is angled in a way that causes this acceleration to keep the satellite in orbit. (Orbits gradually decay as a result of collisions with the small number of air molecules found even at altitudes normally classified as "outer space". ) Solar sails have yet to be used widely to propel spacecraft in this way--several earlier versions came unstuck when the sails failed to unfurl properly-but doing so is not a novel idea in principle The novelty Dr. Lappas envisages is to change the angle of the sail when the satellite has become defunct. Instead of keeping the derelict craft in orbit, it will, over the course of a couple of years, drag it into the atmosphere and thus to a fiery end. Not only that, but the sail will also act like a handkerchief, mopping up microscopic orbital detritus such as flecks of paint from previous launches. A fleck of paint may not sound dangerous, but if travelling at 27 000kph (17 000mph), as it would be in orbit, it could easily penetrate an astronaut's spacesuit. A prototype of Dr. Lappas's design, called CubeSail, will be launched late next year. It weighs just 3kg and, when folded up, measures 30cm (12 inches) by 10era by 10era. Once unfurled, however, the sail will have an area of 25 square metres. If this prototype, which is paid for by EADS, a European aerospace company, proves successful, solar sails might be added to many future satellites. That would enable them to be removed rapidly from orbit when they became useless and would restore to the skies some measure of Aristotelian perfection.

单选题{{B}}Part A{{/B}}{{B}}Text 1{{/B}} Clouds may have silver linings, but even the sunniest of us seldom glimpse them on foot. The marvelous Blur Building that hovers above the lake of Yverdon les Bains in Switzerland provides such an opportunity. It gives anyone who has ever wanted to step into the clouds they watch from the airplane window a chance to realize their dream. Visitors wear waterproof ponchos before setting off along a walkway above the lake that takes them into the foggy atmosphere of the cloud. The experience of physical forms blurring before your eyes as you enter the cloud is both disorientating and liberating. However firmly your feet are planted on the floor, it is hard to escape the sensation of floating. On the upper deck of this spaceship-shaped structure, the Angel Bar, a translucent counter lit in tones of aqueous blue, beckons with a dozen different kinds of mineral water. To enter this sublime building situated in the landscape of the Swiss Alps feels like walking into a poem—it is part of nature but removed from reality, Its architects, Elizabeth Diller and Ricardo Scofidio of New York, designed it as a pavilion for the Swiss Expo 2002 in the Three Lakes region of Switzerland, an hour's train ride from Geneva, which features a series of exhibits on the lakes. The Blur Building is easily the most successful. Indeed, you can skip the rest of the Expo—a Swiss kitsch version of Britain's Millennium Dome—and head straight for the cloud, which is there until the end of October. The architects asked themselves what was the ideal material for building on a lake and decided on water itself.' the element of the lake, the snow. the rivers and the mist above it. They wanted to play on and lay bare the notion of a world's fair pavilion by creating an ethereal ghost of one in which there is nothing to see. The result is a refuge from the surveillance cameras and high-definition images of our everyday world—a particular tease in Switzerland, where clarity and precision are so prized. (Anti- architecture or not, the Blur Building cost a cool $7.5 million.) Out-of-the-box thinking is a trademark of Diller+Scofidio. a husband-and-wife team of architecture professors who became the first architects to win a genius grant from the MacArthur Foundation in 1999. Although they have built very little, they are interested in the social experience of architecture, in challenging people's ideas about buildings. They treat architecture as an analytical art form that combines other disciplines, such as visual art and photography, dance and theatre. To realize its Utopian poetry, the Blur Building has to be technologically state-of-the-art. Water from the lake is pumped through 32.000 fog nozzles positioned throughout the skeleton-like stainless steel structure; so the building does not just look like a cloud on the outside, it feels like a cloud on the inside. And while the 300-foot-wide platform can accommodate up to 400 people, visitors vanish from each other in the mist at about five paces, so you really can wander lonely as a cloud. Wordsworth must be smiling.

单选题 What's your earliest childhood memory? Can you remember learning to walk? Or talk? The first time you heard thunder or watched a television program? Adults seldom{{U}} {{U}} 1 {{/U}} {{/U}}events much earlier than the year or so before entering school,{{U}} {{U}} 2 {{/U}} {{/U}}children younger than three or four{{U}} {{U}} 3 {{/U}} {{/U}}retain any specific, personal experiences. A variety of explanations have been{{U}} {{U}} 4 {{/U}} {{/U}}by psychologists for this "childhood amnesia". One argues that the hippo-campus, the region of the brain which is{{U}} {{U}} 5 {{/U}} {{/U}}for forming memories, does not mature until about the age of two. But the most popular theory{{U}} {{U}} 6 {{/U}} {{/U}}that, since adults don't think like children, they cannot{{U}} {{U}} 7 {{/U}} {{/U}}childhood memories. Adults think in words, and their life memories are like stories or{{U}} {{U}} 8 {{/U}} {{/U}}one event follows{{U}} {{U}} 9 {{/U}} {{/U}}as in a novel or film. But when they search through their mental{{U}} {{U}} 10 {{/U}} {{/U}}for early childhood memories to add to this verbal life story. they don't find any that fit the{{U}} {{U}} 11 {{/U}} {{/U}}It's like trying to find a Chinese word in an English dictionary. Now psychologist Annette Simms of the New York State University offers a new{{U}} {{U}} 12 {{/U}} {{/U}}for childhood amnesia. She argues that there simply aren't any early childhood memories to (13) . According to Dr. Simms, children need to learn to use someone else's spoken description of their personal{{U}} {{U}} 13 {{/U}} {{/U}}in order to turn their own short-term, quickly forgotten {{U}}{{U}} 14 {{/U}} {{/U}}of them into long-term memories. In other{{U}} {{U}} 15 {{/U}} {{/U}}, children have to talk about their experiences and hear others talk about{{U}} {{U}} 16 {{/U}} {{/U}}—Mother talking about the afternoon {{U}}{{U}} 17 {{/U}} {{/U}}looking for seashells at the beach or Dad asking them about their day at Ocean Park. Without this{{U}} {{U}} 18 {{/U}} {{/U}}reinforcement, says Dr. Simms, children cannot form{{U}} {{U}} 19 {{/U}} {{/U}}memories of their personal experiences.{{B}}Notes:{{/B}} childhood amnesia 儿童失忆症。

单选题People don't want to buy information online. Why? Because they don't have to. No more than that because they're used to not paying for it. That's the conventional wisdom. Slate, Microsoft's online politics-and-culture magazine, is an oft-cited example of the failed attempts to charge a fee for access to content. So far, for most publishers, it hasn't worked. But nothing on the Web is a done deal. In September graphics-soft-ware powerhouse Adobe announced new applications that integrate commerce into downloading books and articles online, with Simon Schuster, Barnes and Noble, and Salon. corn among its high-profile partners. Some analysts put the market for digitized publishing at more than $100 billion. Of course, if the Internet can generate that kind of money—some might say almost any kind of money—people want in. And this couldn't come at a better time. Newspaper and magazine writers in particular are increasingly frustrated by their publishers, which post their writings online but frequently don't pay them extra. So here's the good news: Fathrain. com, the third biggest book-seller on the Net—after Amazon. com and Barnesandnoble. corn—is now doing just what the publishing industry that made it a success fears., it's offering a secure way to pay for downloadable manuscripts online. Fatbrain calls it offshoot eMatter. With it, the company's executives have the radical notion of ousting publishers from the book-selling business altogether by giving writers 50% of each and every sale (To reel in authors, eMatter is running a 100% royalty promotion until the end of the year. ) Suggested prices to consumers range from a minimum $ 2 to $ 20, depending on the size of the book to download. "This will change publishing forever!" Chris MaeAskill, co-founder and chief executive of Fatbrain, declares with the bravado of an interior decorator. "With eBay, anybody could sell antiques. Now anybody can be published. " There's been no shortage of authors wanting in. Within a few weeks, according to the company, some 2,000 writers signed on to publish their works. Some of this is technical stuff—Fatbrain got where it is by specializing in technical books—but there are some well-known writers like Catherine Lanigan, author of Romancing the Stone, who has put her out-of-print books and a new novella on the site. Another popular draw is Richard Bach, who agreed to post a 23-page short story to the site. Not everyone thinks downloadable documents are the biggest thing in publishing since Oprah's Book Club. "I think it will appeal to sellers more than buyers," says Michael May, a digitalcommerce analyst at Jupiter Communications, which released a report that cast doubt on the market's potential. "A lot of people are going to publish gibberish. The challenge is to ensure the quality of the work. " Blaine Mathieu, an analyst at Gartner Group's Dataquest, says, "Most people who want digital content want it immediately, I don't know if this model would satisfy their immediate need. Even authors may not find that Web distribution of their works is going to bring them a pot of gold. For one thing, it could undermine sales rather than enhance them. For another, anybody could e-mail downloaded copies of manuscripts around town or around the world over the Net without the writer's ever seeing a proverbial dime. " Softlock. com, Authentica and Fatbrain are trying to head this problem off by developing encryption padlocks that would allow only one hard drive to receive and print the manuscripts. For now, the problem persists.