单选题 Question 26-30 Bust a myth, get a benefit Few subjects harbor more myths and misconceptions than nutrition. Some of the most common: "Low-fat" means "healthy". Low-fat foods can be healthy, but not always. The problem? Many processed foods that are low in fat are high in sugar, which gives you extra calories and may cause wide swings in your blood sugar levels. This makes you gain weight and lose energy, and may raise your risk of several diseases. Some people believe "low-fat" means "Eat all you want. " I remember a dieting patient who was puzzled because he was gaining weight. He mentioned he was eating a low-fat cake. When I asked him bow much, he replied, "Oh, one or two. " "One or two pieces? No, one or two cakes!" An ideal diet is low in fat and low in sugar. Most people can enjoy high-sugar, high-fat treats on occasion, but if you indulge one day, be sure to eat healthier the next. Canned fruits and vegetables aren't nutritious. They can be. A recent review of studies found that nutrients are generally similar in comparable fresh, frozen and canned fruits and vegetables. Many parents have told me that, knowing this, they might be more likely to cook at home rather than eat less nutritious meals at restaurants. Red wine, not white, prevents heart disease. Yes, drinking red wine may significantly decrease the risk of heart disease, but white wine may be just as protective, at least in rats. Resveratrol is a healthy substance found in the skin of red grapes. It's higher in concentration in red wine than white because red wine is fermented with the skins, allowing it to absorb the resveratrol. American and Italian researchers recently found that grape pulp extract (white wine) was equally effective in protecting rats from a heart attack as grape skin extract (red wine). Also, most of the antioxidant benefits of wine come from the grape itself, not the fact that it's fermented. Studies show that spending time with friends and family may reduce the risk of many illnesses. People who imbibe moderately often do so in the company of others, and these psychosocial factors may be as powerful as the drink itself. I neither prescribe nor proscribe alcohol, but if you're going to drink, have no more than one or two four-ounce glasses of wine, one or two beers, or one or two ounces of liquor. More than that and the toxicities of alcohol begin to outweigh any of its potential benefits. Juice is less healthy than whole fruits. Not always. "The view that pure fruit and vegetable juices are nutritionally inferior to fruits and vegetables, in relation to chronic-disease risk reduction, is unjustified," concluded a recent review of studies. The impact of antioxidants on disease risk may be more important than the amount of fiber. Whole fruits and vegetables do have more fiber than most juices, and fiber has many benefits. It fills you up before you get too many calories, and it helps regulate blood sugar. Some juice companies are preserving the pulp (which adds to the fiber) or are even putting it back in. Summer Diet Traps. It's the season for travel, day trips and meals on the run, and it's easier than ever to eat healthy on the road. At airports, look for fresh fruit and packaged salads. Dip your fork in the dressing instead of pouring it on. Amusement parks are providing healthier choices. Disney will eliminate added trans fats from its parks by the end of this year, and kids'meals will include sides like applesauce and carrots—not fries. Some fast-food places offer better choices, too, so you can eat well just about anywhere.

单选题Bust a myth, get a benefit Few subjects harbor more myths and misconceptions than nutrition. Some of the most common: "Low-fat" means "healthy". Low-fat foods can be healthy, but not always. The problem? Many processed foods that are low in fat are high in sugar, which gives you extra calories and may cause wide swings in your blood sugar levels. This makes you gain weight and lose energy, and may raise your risk of several diseases. Some people believe "low-fat" means "Eat all you want. " I remember a dieting patient who was puzzled because he was gaining weight. He mentioned he was eating a low-fat cake. When I asked him bow much, he replied, "Oh, one or two. " "One or two pieces? No, one or two cakes!" An ideal diet is low in fat and low in sugar. Most people can enjoy high-sugar, high-fat treats on occasion, but if you indulge one day, be sure to eat healthier the next. Canned fruits and vegetables aren"t nutritious. They can be. A recent review of studies found that nutrients are generally similar in comparable fresh, frozen and canned fruits and vegetables. Many parents have told me that, knowing this, they might be more likely to cook at home rather than eat less nutritious meals at restaurants. Red wine, not white, prevents heart disease. Yes, drinking red wine may significantly decrease the risk of heart disease, but white wine may be just as protective, at least in rats. Resveratrol is a healthy substance found in the skin of red grapes. It"s higher in concentration in red wine than white because red wine is fermented with the skins, allowing it to absorb the resveratrol. American and Italian researchers recently found that grape pulp extract (white wine) was equally effective in protecting rats from a heart attack as grape skin extract (red wine). Also, most of the antioxidant benefits of wine come from the grape itself, not the fact that it"s fermented. Studies show that spending time with friends and family may reduce the risk of many illnesses. People who imbibe moderately often do so in the company of others, and these psychosocial factors may be as powerful as the drink itself. I neither prescribe nor proscribe alcohol, but if you"re going to drink, have no more than one or two four-ounce glasses of wine, one or two beers, or one or two ounces of liquor. More than that and the toxicities of alcohol begin to outweigh any of its potential benefits. Juice is less healthy than whole fruits. Not always. "The view that pure fruit and vegetable juices are nutritionally inferior to fruits and vegetables, in relation to chronic-disease risk reduction, is unjustified," concluded a recent review of studies. The impact of antioxidants on disease risk may be more important than the amount of fiber. Whole fruits and vegetables do have more fiber than most juices, and fiber has many benefits. It fills you up before you get too many calories, and it helps regulate blood sugar. Some juice companies are preserving the pulp (which adds to the fiber) or are even putting it back in. Summer Diet Traps. It"s the season for travel, day trips and meals on the run, and it"s easier than ever to eat healthy on the road. At airports, look for fresh fruit and packaged salads. Dip your fork in the dressing instead of pouring it on. Amusement parks are providing healthier choices. Disney will eliminate added trans fats from its parks by the end of this year, and kids"meals will include sides like applesauce and carrots—not fries. Some fast-food places offer better choices, too, so you can eat well just about anywhere.

单选题A major study of the grocery-buying habits of millions of Americans released late last year found that people using food stamps generally make the same unhealthy food choices as everyone else in America. Too many sweets, salty snacks and prepared desserts. Junk food, in other words. But when it came to soda and its sugary ilk, the results were more surprising, and not in a good way. According to the USDA-funded study, shoppers using food stamps spent a larger share of their budget—9.25% to be exact—on sugar-sweetened beverages than other shoppers. Even more startling: Food-stamp shoppers bought more soda than any other single grocery item. The new data revived an old debate about banning soda from the $71 billion food-stamp program. In February, the House Agriculture Committee held a hearing to gather testimony about the pros and cons of such a restriction. It does seem counterproductive to spend billions of taxpayer dollars in an effort to improve the nutrition of low-income Americans on a product with little or no nutritional value. It is called the Supplemental Nutrition Assistance Program, after all. And soda had been identified as one of the prime culprits in soaring U.S. obesity and Type 2 diabetes rates. The study and committee debate raised some of the same uncomfortable issues that have caused the proposal to languish in the past. On the conservative side, folks have worried that this type of nannystate regulation will lead to other heavy-handed health-related restrictions. Liberals, meanwhile, have been concerned that it is patronizing and punitive to tell people how to spend their government benefits. Add in the opposition from beverage industry lobby and it"s no surprise this idea hasn"t gotten very far when it"s been proposed. In recent years, a handful of states and cities have tried to impose such a requirement, but were blocked by the U.S. Department of Agriculture. The difference now is that the attitude toward soda has rapidly soured as more evidence has poured in that beverages with added sugars are making people fat and sick. The USDA has issued dietary guidelines warning people to limit their consumption of food with added sugars, the largest sources of which are sweetened beverages. This belief helped San Francisco, Philadelphia and handful of other cities push through new taxes on soda. A handful more are considering their own soda levies. We know that there are detrimental health effects of drinking lots of soda, but we don"t know if barring SNAP recipients from spending their benefits on soda will really improve their health. It"s worth finding out by undertaking a limited pilot program, regardless of the qualms we may have about imposing restraints on the poor that better-off Americans don"t face. The assumption is that those billions of dollars not going to buy Coke will be spent on healthier food. But that may not be the case. What if consumption of other sugary items increases? Or if SNAP recipients simply transferred their sweet drink habit ounce-for-ounce to more expensive and still sugar-laden fruit juice? Or if they spent their non-SNAP money on soda? Before making a permanent change, we need to know if it would improve nutrition or be pointlessly punitive. But it is a good step to take to gather data. And the argument that it would be too hard on grocers to carve out sugary drinks doesn"t hold water. As the study shows, modern grocery check stand technology is sophisticated enough to easily separate out purchases by UPC code. Indeed, SNAP already comes with restrictions on alcohol, tobacco and hot foods. Grocers don"t have a problem sorting them out. The Women, Infant and Children food-assistance program is even more prescriptive, permitting only specific items to be purchased: milk, cheese, cereal and formula, for example, but absolutely nothing with added sugar or artificial sweetener. Ideally, a pilot program would also find ways to improve access to safe drinking water. Denying poor people the ability to use food aid to buy a Coke on a hot day may raise some unsettling questions. Yet the findings in the USDA"s study about excessive soda consumption shouldn"t be ignored.

单选题 In the atmosphere, carbon dioxide acts rather like a one-way mirror—the glass in the roof of a greenhouse which allows the sun's rays to enter but prevents the heat from escaping. According to a weather expert's prediction, the atmosphere will be 3 ℃ warmer in the year 2050 than it is today, if man continues to burn fuels at the present rate. If this warming up took place, the ice caps in the poles would begin to melt, thus raising sea level several meters and severely flooding coastal cities. Also. the increase in atmospheric temperature would lead to great changes in the climate of the northern hemisphere, possibly resulting in an alteration of earth's chief food-growing zones. In the past, concern about a man-made warming of the earth has concentrated on the Arctic because the Antarctic is much colder and has a much thicker ice sheet. But the weather experts are now paying more attention to West Antarctic, which may be affected by only a few degrees of warming, in other words, by a warming on the scale that will possibly take place in the next fifty years from the burning of fuels. Satellite pictures show that large areas of Antarctic ice are already disappearing. The evidence available suggests that a warming has taken place. This fits the theory that carbon dioxide warms the earth. However, most of the fuel is burnt in the northern hemisphere, where temperatures seem to be falling. Scientists conclude, therefore, that up to now natural influences on the weather have exceeded those caused by man. The question is: Which natural cause has most effect on the weather? One possibility is the variable behavior of the sun. Astronomers at one research station have studied the hot spots and "cold" spots (that is, the relatively less hot spots) on the sun. As the sun rotates, every 27.5 days, it presents hotter or "colder" faces to the earth, and different aspects to different parts of the earth. This seems to have a considerable effect on the distribution of the earth's atmospheric pressure, and consequently on wind circulation. The sun is also variable over a long term: its heat output goes up and down in cycles, the latest trend being downward. Scientists are-now finding mutual relations between models of solar-weather interactions and the actual climate over many thousands of years, including the last Ice Age. The problem is that the models are predicting that the world should be entering a new Ice Age and it is not. One way of solving this theoretical difficulty is to assume a delay of thousands of years while the solar effects overcome the inertia of the earth's climate. If this is tight, the warming effect of carbon dioxide might thus be serving as a useful counter-balance to the sun's diminishing heat.

单选题When I recently mentioned to a pregnant acquaintance that I was writing a book about egg freezing (and had frozen my own eggs in hopes of preserving my ability to have children well into my 40s), she replied, "You"re so lucky. I wish I had known to freeze my eggs. " She was 40 years old and wanted two children, so she and her husband were planning to start trying to conceive a second child shortly after the birth of their first. "Now everything is a rush," she said. Married at 38, she didn"t think to talk to her obstetrician-gynecologist about fertility before then. If her doctor had brought up the subject, she said, she might have put away some eggs when she was younger. In our fertility-obsessed society, women can"t escape the message that it"s harder to get pregnant after 35. And yet, it"s not a conversation patients are having with the doctors they talk to about their most intimate issues—their OB-GYNs—unless they bring up the topic first. OB-GYNs routinely ask patients during their annual exams about their sexual histories and need for contraception, but often missing from the list is, "Do you plan to have a family?" OB-GYNs are divided on whether it"s their responsibility to broach the topic with patients. Those who take an "ask me first" approach understandably don"t want to offend women who don"t want children, or frighten those who do. It doesn"t take much for an informational briefing to spiral into a teary heart-to-heart about dating woes. Do you reassure a distraught 38-year-old that she"s still got time; encourage her to seriously consider having a baby on her own; or freak her out so she settles for a lackluster relationship? And considering that fertility figures are averages (while one woman may need fertility treatment at age 36, another can get pregnant naturally at 42), when is the right age to sound the alarm? But the biggest impediment to bringing the issue up was that doctors didn"t have many good recommendations for a single woman. she could either use an anonymous donor"s sperm to have a baby today, or she could fertilize her eggs with it and freeze the resulting embryos for future use. Now, a better option is gaining credibility. Egg freezing (a technique that allows women to store their unfertilized eggs to use with a future partner when they are older) has been available in the United States since the early 2000s, but success rates at first were low and doctors have been hesitant to push it. The American Society for Reproductive Medicine said the technique shouldn"t be "offered or marketed as a means to defer reproductive aging", and deemed it "experimental". Last week, the doctors" society announced that it was removing the experimental label (though it stopped short of endorsing widespread use of egg freezing to put off having children). After reviewing four randomized controlled trials, it found little difference in the effectiveness of using fresh or frozen eggs in in-vitro fertilization, and said that babies conceived from frozen eggs faced no increased risk of birth defects or developmental problems. The procedure isn"t a panacea. It"s terribly expensive—often $15,000—and is not usually covered by insurance. In addition, there"s a worrisome lack of data regarding the success rates of eggs frozen by the women at the end of their baby-making days. The majority of the women in the four studies were under 35, and it warned against giving women who want to delay childbearing "false hope" that their frozen eggs will work when they are ready to get pregnant years later. Although estimates of the number of American women who have frozen their eggs for nonmedical reasons are in the thousands, very few have yet returned to thaw them—there are only a couple of thousand babies born from frozen eggs in the world. Women should be allowed to come to their own conclusions and take their own risks—there"s a fine line between doctors" "mentioning" and "suggesting" the procedure—but this is an option they should be hearing about from their OB-GYNs. To standardize the message, professional groups like the American Congress of Obstetricians and Gynecologists should create pamphlets that doctors can give to patients. OB-GYN residents also can learn suggested scripts that present the information in a nonbiased, non alarmist way. I first learned about egg freezing from a friend who had talked to her OB-GYN about whether she should freeze, given her family"s history of premature menopause. When I asked my doctor about the procedure, she said she had heard that the success rates had recently improved and gave me the name of a respected fertility doctor. As a result, I stashed away several batches of eggs between the ages of 36 and 38—just before the cutoff at which many doctors no longer consider eggs worthwhile to save. I was fortunate, because I knew to ask. We must go one step further and expect OB-GYNs to bring up family planning at every annual visit, so that women have the information they need to choose to take charge of their fertility. Perhaps more women will think about freezing in their early to mid-30s, when their chances of success are greater. Or maybe, after being asked about their plans from their very first visit, more will decide to start families when their eggs are at their prime, and won"t even need to freeze.

单选题Questions 1 to 5 are based on the following conversation.

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单选题LARRY SUMMERS, a Treasury secretary under Bill Clinton, once said that "the world economy is flying on one engine" to describe its excessive reliance on American demand. Now growth seems to be becoming more even at last: Europe and Japan are revving up, as are most emerging economies. As a result, if the American engine stalls, the global aeroplane will not necessarily crash. American consumers have been the main engine not just of their own economy but of the whole world"s. If that engine fails, will the global economy nose-dive? A few years ago, the answer would probably have been yes. But the global economy may now be less vulnerable. At the World Economic Forum in Davos last week, Jim O"Neill, the chief economist at Goldman Sachs, argued convincingly that a slowdown in America need not lead to a significant global loss of power. Start with Japan, where industrial output jumped by an annual rate of 11% in the fourth quarter. Goldman Sachs has raised its GDP growth forecast for that quarter (the official number is due on February 17th) to an annualised 4.2%. That would push year-on-year growth to 3.9%, well ahead of America"s 3.1%. The bank predicts average GDP growth in Japan this year of 2.7%. It thinks strong demand within Asia will partly offset an American slowdown. Japan"s labour market is also strengthening. In December the ratio of vacancies to job applicants rose to its highest since 1992. It is easier to find a job now than at any time since the bubble burst in the early 1990s. Stronger hiring by firms is also pushing up wages after years of decline. Workers are enjoying the biggest rise in bonuses for over a decade. Higher incomes mean more spending: households spent 3.2% more in December than a year earlier. And according to Richard Jerram, of Macquarie Bank, retail sales rose in 2005 for the first full year since 1996. In other words, Japan"s growth is becoming much less dependent on exports. The disappearance of deflation has also reduced real interest rates, giving further support to domestic demand. Even the euro area is emerging from the doldrums. In Germany in particular, vigorous corporate restructuring has boosted productivity and profits. So far, however, this has been at the expense of jobs and wages, and hence of consumer spending—although with capital expenditure picking up, new hiring is likely to follow. Mr O"Neill suggests that Germany is where Japan was 18 months ago. The Ifo survey of German business confidence also indicates that the recovery is spreading to consumers. Retailers" confidence in January rose to its highest for five years. The expectations component of the overall survey rose to its highest since November 1994. If the traditional relationship between Ifo"s business-confidence index and GDP growth holds, then Germany"s economy could grow this year by much more than most economists are forecasting. For the first time in many years, Germany"s domestic demand looks set to contribute more to growth in 2006 than its net exports will. Elsewhere in the euro area, domestic demand has been the main source of growth in any case. According to Morgan Stanley, since 1999 it has supplied 95% of the zone"s GDP growth. These economies are therefore more resistant to external shocks than is generally thought. Although Germany is leading the pack, businesses throughout the euro area are feeling perkier. The European Commission"s survey of business sentiment rose healthily in January, to a level that could signal GDP growth of well above the consensus forecast of 2% for this year. Alongside stronger domestic demand in Europe and Japan, emerging economies are also tipped to remain robust. These economies are popularly perceived as excessively export-dependent, flooding the world with cheap goods, but doing little to boost demand. Yet calculations by Goldman Sachs show that Brazil, Russia, India and China combined have in recent years contributed more to the world"s domestic demand than to its GDP growth. They have chipped in almost as much to global domestic demand as America has. If this picture endures, a moderate slowdown in America need not halt the expansion in the rest of the world. Europe and Japan together account for a bigger slice of global GDP than the United States, so faster growth there will help to keep the global economy flying. A rebalancing of demand away from America to the rest of the world would also help to shrink its huge current-account deficit. This all assumes that America"s economy slows, rather than sinks into recession. The world is undoubtedly better placed to cope with a slowdown in the United States than it was a few years ago. That said, in those same few years America"s imbalances have become larger, with the risk that the eventual correction will be more painful. A deep downturn in America would be felt all around the globe.

单选题 Questions 23-26

单选题On the worst days, Chris Keehn used to go 24 hours without seeing his daughter with her eyes open. A soft-spoken tax accountant in Deloitte's downtown Chicago office, he hated saying no when she asked for a ride to preschool. By November, he'd had enough. "I realized that I can have control of this," he says with a small shrug. Keehn, 33, met with two of the firm's partners and his senior rmanager, telling them he needed a change. They went for it. In January, Keehn started telecommuting four days a week, and when Kathryn, 4, starts T-ball this summer, he will be sitting along the baseline. In this economy, Keehn's move might sound like hopping onto the mommy track--or off the career track. But he’s actually making a shrewd move. More and more, companies are searching for creative ways to save--by experimenting with reduced hours or unpaid furloughs or asking employees to move laterally. The up-or-out model, in which employees have to keep getting promoted quickly or get lost, may be growing outmoded. The changing expectations could persist after the economy reheats. Companies are increasingly supporting more natural growth, letting employees wend their way upward like climbing vines. It's a shift, in other words, from a corporate ladder to the career-path metaphor long preferred by Deloitte vice chair Cathy Benko: a lattice. At Deloitte, each employee's lattice is nailed together during twice-a-year evaluations focused not just on career targets but also on larger life goals. An employee can request to do more or less travel or client service, say, or to move laterally into a new role--changes that may or may not come with a pay cut. Deloitte's data from 2008 suggest that about 10% of employees choose to "dial up" or "dial down" at any given time. Deloitte's Mass Career Customization (MCC) program began as away to keep talented women in the workforce, but it has quickly become clear that women are not the only ones seeking flexibility. Responding to millennials demanding better work-life balance, young parents needing time to share child-care duties and boomers looking to ease gradually toward retirement, Deloitte is scheduled to roll out MCC to all 42,000 U. S. employees by May 9,010.Deloitte executives are in talks with more than 80 companies working on similar programs. Not everyone is on board. A 33-year-old Deloitte senior manager in a southeastern office, who works half-days on Mondays and Fridays for health reasons and requested anonymity because she was not authorized to speak on the record, says one "old school" manager insisted on scheduling meetings when she wouldn't be in the office. "He was like, "Yeah, I know we have the program, '"she recalls, "'but I don't really care. '" Deloitte CEO Barry Salzberg admits he's still struggling to convert "nonbelievers," but says they are the exceptions. The recession provides an incentive for companies to design more lattice-oriented careers. Studies show telecommuting, for instance, can help businesses cut real estate costs20% and payroll 10%. What's more, creating a flexible workforce to meet staffing needs in a changing economy ensures that a company will still have legs when the market recovers. Redeploying some workers from one division to another-or reducing their salaries--is a whole lot less expensive than laying everyone off and starting from scratch. Young employees who dial down now and later become managers may reinforce the idea that moving sideways on the lattice doesn't mean getting sidelined. "When I saw other people doing it," says Keehn, "I thought I could try. " As the compelling financial incentives for flexibility grow clearer, more firms will be forced to give employees that chance. Turns out all Keehn had to do was ask.

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单选题There are several different methods that can be used to create a forecast. The method a forecaster chooses depends upon the experience of the forecaster, the amount of information available to the forecaster, the level of difficulty that the forecast situation presents, and the degree of accuracy or confidence needed in the forecast. The first of these methods is the persistence method; the simplest way of producing a forecast. The persistence method assumes that the conditions at the time of the forecast will not change. For example, if it is sunny and 87 degree today, the persistence method predicts that it will be sunny and 87 degree tomorrow. If two inches of rain fell today, the persistence method would predict two inches of rain for tomorrow. However, if weather conditions change significantly from day to day, the persistence method usually breaks down and is not the best forecasting method to use. The trends method involves determining the speed and direction of movement for fronts, high and low pressure centers, and areas of clouds and precipitation. Using this information, the forecaster can predict where he or she expects those features to be at some future time. For example, if a storm system is 1,000 miles west of your location and moving to the east at 250 miles per day, using the trends method you would predict it to arrive in your area in 4 days. The trends method works well when systems continue to move at the same speed in the same direction for a long period of time. If they slow down, speed up, change intensity, or change direction, the trends forecast will probably not work as well. The climatology method is another simple way of producing a forecast. This method involves averaging weather statistics accumulated over many years to make the forecast. For example, if you were using the climatology method to predict the weather for New York City on July 4th, you would go through all the weather data that has been recorded for every July 4th and take an average. The climatology method only works well when the weather pattern is similar to that expected for the chosen time of year. If the pattern is quite unusual for the given time of year, the climatology method will often fail. The analog method is a slightly more complicated method of producing a forecast. It involves examining today"s forecast scenario and remembering a day in the past when the weather scenario looked very similar (an analog). The forecaster would predict that the weather in this forecast will behave the same as it did in the past. The analog method is difficult to use because it is virtually impossible to find a predict analog. Various weather features rarely align themselves in the same locations they were in the previous time. Even small differences between the current time and the analog can lead to very different results.

单选题 {{B}}Questions 27—30{{/B}}

单选题An experimental treatment for Parkinson"s disease seemed to improve symptoms—dramatically so, for one 59-year-old man—without causing side effects in an early study of a dozen patients. The gene therapy treatment involved slipping billions of copies of a gene into the brain to calm overactive brain circuitry. More than half a million Americans have Parkinson"s. They endure symptoms that include tremors, rigidity in their limbs, slowness of movement and impaired balance and coordination. Eventually they can become severely disabled. The small study focused on testing the safety of the procedure rather than its effectiveness, and experts cautioned it"s too soon to draw conclusions about how well it works. But they called the results promising and said the approach merits further studies. "We still have quite a bit more testing to do," said Dr. Michael Kaplitt of Weill Cornell Medical College in New York, an author of the study. Still, "the initial results are extremely encouraging". Nathan Klein, a 59-year-old freelance television producer in Port Washington, N.Y., said the disease left him "pretty messed up". It weakened his voice, impaired his walking and made his hand tremble so badly he couldn"t hold a glass of wine without spilling it all. Klein was the first patient to be treated with Kaplitt"s gene therapy procedure in 2003, and he said his symptoms gradually subsided afterward. Nowadays, he said, apart from freezing now and then when he wants to walk, the symptoms are basically gone. "I"m elated," said Klein, who continues to take his regular pills for the disease. "It"s unbelievable." Kaplitt, who has a financial interest in Neurologix Inc., which paid for the research, noted that the 12 patients in the study still have Parkinson"s symptoms. The amount of medication they were already taking for their symptoms didn"t change significantly in the year after the surgery. Current medicines can control symptoms, but can"t stop the disease from getting worse over time, and they can produce troublesome side effects like uncontrollable movement. Some patients gain relief from a surgical treatment called deep brain stimulation, in which electrodes are placed in the brain and connected to a programmable stimulator. Kaplitt"s procedure was aimed at achieving the same goal as that surgery, calming overactive circuitry in the brain. It gets overactive because it loses the normal supply of a chemical called GABA. The gene therapy was designed to make the brain produce more GABA. For the gene therapy surgery, a tube about the width of a hair was threaded through a hole about the size of a quarter at the top of the skull. The tube delivered a dose of a virus engineered to ferry copies of a gene into cells of a brain region called the subthalamic nucleus. The gene copies enable the cells to pump out more GABA.

单选题

单选题Questions 21～25 Next month a large group of British business people are going to America on a venture which may generate export earnings for their companies' shareholders in years to come. A long list of sponsors will support the initiative, which will involve a ￡3-million media campaign and a fortnight of events and exhibitions. The ultimate goal is to persuade more Americans that British companies have something to interest them. While there have been plenty of trade initiatives in the past, the difference this time round is that considerable thinking and planning have gone into trying to work out just what it is that Americans look for in British products. Instead of exclusively promoting the major corporations, this time there is more emphasis on supporting the smaller, more unusual, niche businesses. Fresh in the memories of all those concerned is the knowledge that America has been the end of many a large and apparently successful business. For Carringtons, a retail group much respected by European customers and investors, America turned out to be a commercial disaster and the belief that they could even show some of the great American stores a retailing trick or two was hopelessly over-optimistic. Polly Brown, another very British brand that rode high for years on good profits and huge city confidence, also found that conquering America, in commercial and retailing terms, was not as easy as it had imagined. When it positioned itself in the US as a niche, luxury brand, selling shirts that were priced at $40 in the UK for $125 in the States, the strategy seemed to work. But once its management decided it should take on the middle market, this success rapidly drained away. It was a disastrous mistake and the high cost of the failed American expansion plans played a large role in its declining fortunes in the mid-nineties. Sarah Scott, managing director of Smythson, the upmarket stationer, has had to think long and hard about what it takes to succeed in America and she takes it very seriously indeed. "Many British firms are quite patronizing about the US," she says. "They think that we're so much more sophisticated than the Americans. They obviously haven't noticed Ralph Lauren, an American who has been much more skilled at tapping into an idealized Englishness that any English company. Also, many companies don't bother to study the market properly and think that because something's successful in the UK, it's bound to be successful over there. You have to look at what you can bring them that they haven't already got. On the whole, American companies are brilliant at the mass, middle market and people who've tried to take them on at this level have found it very difficult. " This time round it is just possible that changing tastes are running in Britain's favour. The enthusiasm for massive, centralized retail chains has decreased. People want things with some fort of individuality; they are fed up with the banal, middle-of-the-road taste that America does so well. They are now looking for the small, the precious, the 'real thing', and this is precisely what many of the companies participating in the initiative do best.

单选题 What is money? That is not so simple a question as might appear. In fact, money can only be defined in terms of the functions it performs—that is, by the need it fulfills. As Sir Ralph Hawtrey once noted, "Money is one of those concepts which, like a teaspoon or an umbrella, but unlike an earthquake or a buttercup, are definable primarily by the use or purpose which they serve." Money is anything, regardless of its physical or legal characteristics, that customarily and principally performs certain functions. Three such functions are usually specified, corresponding to the three basic needs served by money—the need for a medium of exchange, the need for a unit of account, and the need for a store of value. Most familiar is the first, the function of a medium of exchange, whereby goods and services are paid for and contractual obligations discharged. In performing this role the key attribute of money is general acceptability in the settlement of debt. The second function of money, that of a unit of account, is to provide a medium of information—a common denominator or numeraire in which goods and services may be valued and debts expressed. In performing this role money is said to be a "standard of value" or "measure of value" in valuing goods and services and a "standard of deferred payment" in expressing debts. The third function of money, that of a store of value, is to provide a means of holding wealth. The development of money was one of the most important steps in the evolution of human society, comparable in the words of one writer "with the domestication of animals, the cultivation of the land, and the harnessing of power". Before money there was only barter, the archetypical economic transaction, which required an inverse double coincidence of wants in order for exchange to occur. The two parties to any transaction each had to desire what the other was prepared to offer. This was an obviously inefficient system of exchange since large amounts of time had to be devoted to the necessary process of search and bargaining. Under even the most elemental circumstances barter was unlikely to exhaust all opportunities for advantageous trade. Bartering is costly in ways too numerous to discuss. Among others, bartering requires an expenditure of time and the use of specialized skills necessary for judging the commodities that are being exchanged. The more advanced the specialization in production and the more complex the economy, the costlier it will be to undertake all the transactions necessary to make any given good reach its ultimate user by using barter. The introduction of generalized exchange intermediaries cut the Gordian knot of barter by decomposing the single transaction of sale and purchase, thereby obviating the need for a double coincidence of wants. This served to facilitate multilateral exchange; the costs of transactions reduced, exchange ratios could be more efficiently equated with the demand and supply of goods and services. Consequently, specialization in production was promoted and the advantages of economic division of labor became attainable all because of the development of money. The usefulness of money is inversely proportional to the number of currencies in circulation. The greater the number of currencies, the less is any single money able to perform efficiently as a lubricant to improve resource allocation and reduce transaction costs. Diseconomies remain because of the need for multiple price quotations (diminishing the information savings derived from money's role as unit of account) and for frequent currency conversions (diminishing the stability and predictability of purchasing power derived from money's roles as medium of exchange and store of value). In all national societies there has been a clear historical tendency to limit the number of currencies, and eventually to standardize the domestic money on just a single currency issued and managed by the national authorities. The result has been a minimization of total transaction costs within nation-states. Between nation-states, however, costs or transactions remain relatively high because the number of currencies remains high. Does this suggest that global efficiency would be maximized if the number of currencies in the world were minimized? Is this the optimal organizational principle for international monetary relations? Not necessarily. It is true that total transaction costs, other things being equal, could be minimized by standardizing on just a single global money. "On the basis of the criterion of maximizing the usefulness of money, we should have a single world currency." But there are other criteria of judgment as well. Economic efficiency, as I have indicated, is a multi-variate concept. And we shall soon see that the costs of a single world currency or its equivalent, taking full account of both the single microeconomic benefit of lower transaction costs.