单选题Who is the head of this delegation?A. captainB. leaderC. bestD. capital

单选题The company recommended that a new gas station be built here.

单选题Natural Medicine Since earliest days, humans have used some kinds of medicines. We know this because humans have survived. Ancient treatments for injury and disease were successful enough to keep humans from dying out completely. They were successful long before the time of modem medicine. Before the time of doctors with white coats and shiny (发亮的) instruments. Before the time of big hospitals with strange and wonderful equipment. Many parts of the world still do not have university-educated doctors. Nor do they have expensive hospitals. Yet injuries are treated. And diseases are often cured, how? By ancient methods. By medicines that might seem mysterious, even magical (有魔力的). Traditional medicines are neither mysterious nor magical, however. Through the centuries, tribal (部落的) medicine men experimented with plants. They found many useful chemicals in the plants. And scientists believe many of these traditional medicines may provide the cure for some of today"s most serious diseases. Experts say almost 80% of the people in the world use plants for health care. These natural medicines are used not just because people have no other form of treatment. They are used because people trust them. In developed areas, few people think about the source of the medicines they buy in a store. Yet many widely-used medicines are from ancient sources, especially plants. Some experts say more than 25 % of modern medicines come, in one way or another, from nature. Scientists have long known that nature is really a chemical factory. All living things contain chemicals that help them survive. So scientists" interest in traditional medicine is not new. But it has become an urgent concern. This is because the earth"s supply of natural medicines may be dropping rapidly.

单选题You have to be patient if you want to sustain your position.

单选题It is no use {{U}}debating{{/U}} the relative merits of this policy. A. making B. taking C. expecting D. discussing

单选题Don"t irritate her. she"s on a short fuse today.

单选题You mustn' t delay ______ the medicine over.A. to sendB. sendingC. sentD. send

单选题How often should the employees exercise to help lower the health-care costs?

单选题You look smart in the new suit.

单选题The Wasteland A new catastrophe faces Afghanistan. The American bombing campaign is conspiring with years of civil conflict and drought to create an environmental crisis. Humanitarian and political concerns are dominating the headlines. But they are also masking the disappearance of the country"s once rich habitat and wildlife, which are quietly being crushed by war. The UN is dispatching a team of investigators to the region next month to evaluate the damage. "A healthy environment is a prerequisite for rehabilitation," says Klaus Topfer, head of the UN Environment Programme. Much of south-east Afghanistan was once lush forest watered by monsoon rains. Forests now cover less than 2 percent of the country. "The worst deforestation occurred during Taliban rule, when its timber mafia denuded forests to sell to Pakistani markets," says Usman Qazi, an environmental consultant based in Quetta, Pakistan. And the intense bombing intended to flush out the last of the Taliban troops is destroying or burning much of what remains. The refugee crisis is also wrecking the environment, and much damage may be irreversible. Forests and vegetation are being cleared for much-needed farming, but the gains are likely to be only short-term. "Eventually the land will be unfit for even the most basic form of agriculture," warns Hammad Naqi of the World Wide Fund for Nature in Pakistan. Refugees—around 4 million as the last count—are also cutting into forests for firewood. The hail of bombs falling on Afghanistan is making life particularly hard for the country"s wildlife. Birds such as the pelican and endangered Siberian crane cross eastern Afghanistan as they follow one of the world"s great migratory thoroughfares from Siberia to Pakistan and India. But the number of the birds flying across the region has dropped by a staggering 85 percent. "Cranes are very sensitive and they do not use the route if they see any danger," says Ashiq Ahgmad, an environmental scientist for the WWF in Peshawar, Pakistan, who has tracked the collapse of the birds" migration this winter. The rugged mountains also usually provide a safe haven for mountain leopards, gazelles, bears and Marco Polo sheep—the world"s largest species. "The same terrain that allows fighters to strike and disappear back into the hills has also historically enabled wild life to survive," says Peter Zahler of the Wildlife Conservation society, based in New York. But he warns they are now under intense pressure from the bombing and invasions of refugees and fighters. For instance, some refugees are hunting rare snow leopards to buy a safe passage across the border. A single fur can fetch $2,000 on the black market, says Zahler. Only 5,000 or so snow leopards are thought to survive in central Asia and less than 100 in Afghanistan, their numbers already decimated by extensive hunting and smuggling into Pakistan before the conflict. Timber, falcons and medicinal plants are also being smuggled across the border. The Taliban once controlled much of this trade, but the recent power vacuum could exacerbate the problem. Bombing will also leave its mark beyond the obvious craters. Defence analysts say that while depleted uranium has been used less in Afghanistan than in the Kosovo conflict, conventional explosives will litter the country with pollutants. They contain toxic compounds such as cyclonite, a carcinogen, and rocket propellants contain perchlorates, which damage thyroid glands.

单选题Eat to Live A. meager diet may give you health and long life, but it's not much fun — and it might not even be necessary. We may be able to hang on to most of that youthful vigor even if we don't start to diet until old age. Stephen Spindler and his colleagues from the University of California at Riverside have found that some of an elderly mouse's liver genes can be made to behave as they did when the mouse was young simply by limiting its food for four weeks. The genetic rejuvenation won't reverse other damage caused by time for the mouse, but could help its liver metabolize drugs or get rid of toxins. Spindler's team fed three mice a normal diet for their whole lives, and fed another three on half-rations. Three more mice were switched from the normal diet to half-feed for a month when they were 34 months old — equivalent to about 70 human years. The researchers checked the activity of 11,000 genes from the mouse livers, and found that 46 changed with age in the normally fed mice. The changes were associated with things like inflammation and free radical production — probably bad news for mouse health. In the mice that had dieted all their lives, 27 of those 46 genes continued to behave like young genes. But the most surprising finding was that the mice that only started dieting in old age also benefited from 70 per cent of these gene changes. "This is the first indication that these effects kick in pretty quickly, " says Huber Warner from the National Institute on Aging near Washington D. C. No one yet knows if calorie restriction works in people as it does in mice, but Spindler is hopeful. "There's attracting and tempting evidence out there that it will work, " he says. If it does work in people, there might be good reasons for rejuvenating the liver. As we get older, our bodies are less efficient at metabolizing drugs, for example. A brief period of time of dieting, says Spindler, could be enough to make sure a drug is effective. But Spindler isn't sure the trade-off is worth it. "The mice get less disease, they live longer, but they're hungry, " he says. "Even seeing what a diet does, it's still hard to go to a restaurant and say: 'I can only eat half of that' . " Spindler hopes we soon won't need to diet at all. His company, Lifespan Genetics in California, is looking for drugs that have the effects of calorie restriction.

单选题It"s almost 5 o"clock, time to quit .

单选题From the perspective of disease, we are all one people on this planet, divided by risk more on the basis of wealth than of geography. This flu will not be deadly for 99.9 percent of those it infects, and that's a good thing not only for infected individuals like me but for the world as a whole. Why? Because we have utterly flailed the globalization test in our response to H1N1. The most effective tool in fighting flu is a good vaccine, and the pharmaceutical industry is working on manufqcturing supplies right now. According to the World Health Organization. about 1 billion doses of H1N1 vaccine have been ordered worldwide. But more than 1/2 billion people live on Earth. From the get - go, some 85 percent of the world's population wil be excluded from what, were this a virulent (危险的，迅速致命的) influenza, would be the primary life- sparing medicine. Worse, those 1 billion orders have been prioritized, with the wealthiest nations at the top of the list. This effectively means that before New Year's Eve only about 5 percent of the world population will have been immunized. What is the author's attitude towards the fact that the wealthiest nations have the priority to order the vaccine against H1N1?A. IndifferentB. CriticalC. NeutralD. Supportiv

单选题The study was the first to tell the difference between 7 and 8 hours of sleep a night?

单选题{{B}}第三篇{{/B}} Oil and Economy Could the bad old days of economic decline be about to return? Since OPEC agreed to supply cuts in March, the price of crude oil has jumped to almost $ 26 a barrel, up from less than $10 last December. This near,tripling of oil prices calls up scary memories of the 1973 oil shock, when prices quadrupled, and 1979-1980, when they also almost tripled. Both previous shocks resulted in double-digit inflation and global economic decline. So where are the headlines warning of gloom and doom this time? The oil price was given another push up this week when Iraq suspended oil exports. Strengthening economic growth, at the same time as winter grips the northern hemisphere, could push the price higher still in the short term. Yet there are good reasons to expect the economic consequences now to be less severe than in the 1970s. In most countries the cost of crude oil now accounts for a smaller share of the price of petrol than it did in the 1970s. In Europe, taxes account for up to four-fifths of the retail price, so even quite big changes in the price of crude have a more muted effect on pump prices than in the past. Rich economies are also less dependent on oil than they were, and so less sensitive to swings in the oil price. Energy conservation, a shift to other fuels and a decline in the importance of heavy, energy-intensive industries have reduced oil consumption. Software, consuhancy and mobile telephones use far less oil than steel or car production. For each dollar of GDP (inconstant prices) rich economies now use nearly 50% less oil than in 1973. The OECD estimates in its latest Economic Outlook that, if oil prices averaged $ 22 a barrel for a full year, compared with $13 in 1998, this would increase the oil import bill in rich economies by only 0.25-0.5% of GDP. That is less than one-quarter of the income loss in 1974 or 1980. On the other hand, oil-importing emerging economies-to which heavy industry has shifted—have become more energy-intensive, and so could be more seriously squeezed. One more reason not to lose sleep over the rise in oil prices is that, unlike the rises in the 1970s, it has not occurred against the background of general commodity-price inflation and global excess demand. A sizable portion of the world is only just emerging from economic decline. The Economist's commodity price index is broadly unchanging from a year ago. In 1973 commodity prices jumped by 70%, and in 1979 by almost 30%.

单选题The boys broke into excited cheering.

单选题During the Second World War, all important resources in the US were {{U}}allocated{{/U}} by the Federal government. A. nationalized B. commandeered C. taxed D. distributed

单选题The manager allocates duties to the clerks.

单选题 Silent and Deadly Transient ischemic attacks (TIAS), or mini-strokes, result from temporary interruptions of blood flow to the brain. Unlike full strokes, they present symptoms lasting anywhere from a few seconds to 24 hours. Rarely do they cause permanent neurological damage, but they are often precursors of a major stroke. "Our message is quite clear," says Dr. Robert Adams, professor of neurology at the Medical College of Georgia in August. "TIAS, while less severe than strokes in the short term, are quite dangerous and need a quick diagnosis and treatment as well as appropriate follow-up to prevent future injury." Unfortunately, mini-strokes are greatly under diagnosed. A study conducted for the National Stroke Association indicates that 2.5% of all adults aged 18 or older (about 4.9 million people in the U. S. ) have experienced a confirmed TIA. An additional 1.2 million Americans over the age of 45, the study showed, have most likely suffered a mini-stroke without realizing it. These findings suggest that if the public knew how to spot the symptoms of stroke, especially mini-strokes, and sought prompt medical treatment, thousands of lives could he saved and major disability could be avoided. The problem is that the symptoms of a mini-stroke are often subtle and passing. Nonetheless, there are signs you can look out for: *Numbness or weakness in the face, arm or leg, especially on one side of the body. *Trouble seeing in one or both eyes. *Confusion and difficulty speaking or understanding. *Difficulty walking, dizziness or loss of coordination. *Severe headache with no known cause. Along with these symptoms, researchers have identified some key indicators that increase your chances of having a full-blown stroke after a TIA: if you're over 60, have experienced symptoms lasting longer than 10 minutes, feel weak and have a history of diabetes. As with many diseases, you can help yourself by changing your lifestyle. The first things you should do are quit smoking, limit your intake of alcohol to no more than a drink or two a day and increase your physical activity. Even those who suffer from high blood pressure or diabetes can improve their odds—and minimize complications if they do have a stroke—by keeping their illness under control. If you experience any of the symptoms, your first call should be to your doctor. It could be the call that saves your life.

单选题How to Use the Sense of Smell Our sense of smell, which we normally take for granted, is nowadays being increasingly used for purposes which might surprise us if we aware of them. One area in which smells are created to achieve particular results is marketing. For some time manufacturers have taken advantage of our sense of smell with regard to household goods. Millions of dollars are spent on product research in the hunt for the right smell as it is believed perfume influnences the way consumers perceive a brand. In a survey in the United States, when people were asked what was the most important factor in their choice of detergent (洗衣粉) , smell was rated highly, above ingredients and price. Now stores are becoming even more direct in their use of smell. The smell of fresh bread in a supermarket tends to encourage people to buy, and people selling their houses are recommended to have coffee being heated when potential buyers arrive. Suddenly smell is becoming big business. One company specializing in the use of smells to attract customers now has many large stores on its own list of customers. They find that when pleasant smells are filtered through a store's air condition system, people tend to spend longer in the store and buy more. Reserch shows that smells can increase people's view of the value of a product. In a test, people looked at the same types of shoes in two rooms--one filled with purified air, the other with a smell of mixed flowers, of the people preferred the shoes in the room with the smell of flowers. In fact, many said they would be prepared to pay up to US$10 more for a pair. Smells also have other potential uses. Some companies are experimenting with different smells to produce different effects in their workers according to the time of day. For example, early in the morning they might put the smell of lemon in the air conditioning system to wake people up. In the middle of the morning, when the atmosphere tends to become more tense, the smell of wood could be used to calm people down. Before lunchtime the smell of melting butter would encourage people to go to lunch on time . After lunch, when people often begin to lose concentration, the smell of mint (薄荷) would increase their alertness.