单选题Whenever people go and live in another country they have new experiences and new feelings. They experience culture shock. Many people have a(n) 【C1】______about culture shock they think that it"s just a feeling of sadness and homesickness when a person is in a new country. But this isn"t really true. Culture shock is a completely natural【C2】______. and everybody goes【C3】______it in a new culture. There are four stages, or steps, in culture shock. When people first arrive in a new country they"re usually excited and【C4】______Everything is interesting. They notice that a lot of things are【C5】______their own culture and this surprises them and makes them happy. This is Stage One In Stage Two people notice how different the new culture is from their own culture. They become confused It seems difficult to do even very simple things. They feel【C6】______They spend a lot of time【C7】______or with other people from their own country. They think "My problems are all because I"m living in this country" Then in Stage Three they begin to understand the new culture better They begin to like some new customs. They【C8】______some people in the new country. They"re【C9】______comfortable and relaxed. In Stage Four they feel very comfortable. They have good friends in the new culture. They understand the new customs. Some customs are similar to their culture and some are different but that"s OK. They can【C10】______it.

单选题The men set off in silence. Pedro walked with his dog a few paces behind the boys. When neighbors saw them walking along in this formation they would say that Pedro looked like a veritable patron striding behind his peons. Yet there were mornings when Pedro talked to the boys in the course of their two-hour walk to the fields, giving advice or telling what work had to be done. The boys, however, spoke only in answer to a question. Out of their father" s earshot they would joke about their sweethearts or visits to the saloons of Cuahnahuac. But this morning they moved silently down the road. It was still barely light. All around them, just beyond the far edges of the fields, the blue-green slopes of the pine-covered mountains rose through the morning mist. Pedro and Ricardo were headed for the mountain slope cornfield which they had cleared the year before. This was communal land belonging to the municipality which consisted of seven villages; anyone could work it. New clearings had to be made every two or three years, for heavy rains washed the topsoil away. To acquire new fields Pedro and his sons burned the brush and weeds, cut down young trees, and built new stone fences. The boys worked well; they had the largest mountain clearing in Azteca. But the crops could supply enough corn and beans for only three or four months. So Pedro had to try other means of earning a living as well — making rope from maguey fiber, selling plums, hiring out his sons as farm hands. One thing he would not do to earn money was to make charcoal for sale, as so many of his neighbors did. This practice, he knew, was wasteful of the precious oak and pine forests and ultimately ruined land. He had been one of the leaders in the struggle for the preservation of the communal forest lands. So he made charcoal only once a year and only for the use of his family.

单选题Monkeys and chimpanzees, although they are weaker and less fierce than many other animals, possess brains which are 55 far along the evolutionary road as any creature other than man. Birds can perform marvels of aerobatics, they can catch insects on the wing with unparalleled skill, they can navigate in a remarkable manner half round the world and back—but they cannot think and reason. In technical terms it can be said that they are lacking in insight. The abilities which they do possess are built-in instincts derived from their genetic inheritance. Monkeys, on the other hand, can reason. They can easily remember a lighted door indicating the presence of food. They can remember what kind of food they are looking for. A monkey set the problem of reaching a banana, say, hung high up in its cage, can work out a system for getting it even if it involves piling up boxes to stand on and then knocking down the banana with a stick. A charming story is told about the psychologist Wolfgang Kobler, who had provided various boxes and other apparatuses by which he proposed to test a chimpanzee"s ability to think out a method of reaching a fruit hung nine feet in the air. The animal looked about it and sized up the problem. Then it took Kobler by the hand, led him to a position immediately under the banana, jumped up on to his shoulder and reached it down from there. But evolution, although it has brought monkeys to a remarkable degree of cleverness, has stopped short at a crucial ability, the possession of which places man at a clearly superior level. Their minds cannot cope with abstract ideas. For example, an ape can be taught to fill a can with water from a barrel and take the can of water to put out a fire so that it can reach into a box and get food. But if the whole set-up is arranged on a raft the animal will continue to draw its water only from the barrel. It can not grasp that any water, taken more, conveniently, say, from the pond on which the raft is floating, will pot out the fire just as well. The abstract idea that water puts out fire is beyond it.

单选题There were red faces at one of Britain" s biggest banks recently. They had accepted a telephone order to buy $ 100,000 worth of shares from a fifteen-year-old schoolboy(they thought he was twenty-one). The shares fell in value and the schoolboy was unable to【C1】______The band lost $ 20,000 on the【C2】______that it cannot get back because, for one thing, this young speculator does not have the money and, for another,【C3】______under eighteen, he is not legally liable for his debts. If the shares had risen in value by the same amount that they fell, he would have pocketed $ 20,000 【C4】______Not bad for a fifteen-year-old. It certainly is better than【C5】______the morning newspaper. In another recent case, a boy of fourteen found, in his grandfather" s house, a suitcase full of foreign banknotes. The clean, crisp banknotes looked very【C6】______but they were now not used in their country of origin or anywhere else. This young boy【C7】______straight to the nearest bank with his pockets filled with notes. The cashiers did not realize that the country in【C8】______had reduced the value of its currency by 90%. They exchanged the notes at their face value at the current exchange rate. In three days, before he was found out, he took $200,000 from nine different banks. 【C9】______, he had already spent more than half of this on taxi-rides, restaurant meals, concert tickets and presents for his many new girlfriends(at least he was generous!)before the police caught up with him. Because he is also under eighteen the banks have【C10】______a lot of money, and several cashiers have lost their jobs.

单选题The biggest problem facing Chile as it promotes itself as a tourist destination to be reckoned with, is that it is at the end of the earth. It is too far south to be a convenient stop on the way to anywhere else and is much farther than a relatively cheap half-day"s flight away from the big tourist markets, unlike Mexico, for example. Chile, therefore, is having to fight hard to attract tourists, to convince travelers that it is worth coming halfway round the world to visit. But it is succeeding, not only in existing markets like the USA and Western Europe but in new territories, in particular the Far East. Markets closer to home, however, are not being forgotten. More than 50% of visitors to Chile still come from its nearest neighbor, Argentina, where the cost of living is much higher. Like all South American countries, Chile sees tourism as a valuable earner of foreign currency, although it has been far more serious than most in promoting its image abroad. Relatively stable politically within the region, it has benefited from the problems suffered in other areas. In Peru, guerrilla warfare in recent years has dealt a heavy blow to the tourist industry and fear of street crime in Brazil has reduced the attraction of Rio de Janeiro as a dream destination for foreigners. More than 150,000 people are directly involved in Chile"s tourist sector, an industry which earns the country more than US $ 950 million each year. The state-run National Tourism Service, in partnership with a number of private companies, is currently running a worldwide campaign, taking part in trade fairs and international events to attract visitors to Chile. Chile"s great strength as a tourist destination is its geographical diversity. From the parched Atacama Desert in the north to the Antarctic snowfields of the south, it is more than 5,000km long. With the Pacific on one side and the Andean mountains on the other, Chile boasts natural attractions. Its beaches are not up to Caribbean standards but resorts such as Vina del Mar are generally clean and unspoilt and have a high standard of services. But the tromp card is the Andes mountain range. There are a number of excellent ski resorts within one hour"s drive of the capital, Santiago, and the national parks in the south are home to rare animal and plant species. The parks already attract specialist visitors, including mountaineers, who come to climb the technically difficult peaks, and fishermen, lured by the salmon and trout in the region"s rivers. However, infrastructural development in these areas is limited. The ski resorts do not have as many lifts and pistes as their European counterparts and the poor quality of roads in the south means that only the most determined travelers see the best of the national parks. Air links between Chile and the rest of the world are, at present, relatively poor. While Chile"s two largest airlines have extensive networks within South America, they operate only a small number of routes to the United States and Europe, while services to Asia are almost non-existent. Internal transport links are being improved and luxury hotels are being built in one of its national parks. Nor is development being restricted to the Andes. Easter Island and Chile"s Antarctic Territory are also on the list of areas where the Government believes it can create tourist markets. But the rush to open hitherto inaccessible areas to mass tourism is not being welcomed by everyone. Indigenous and environmental groups, including Greenpeace, say that many parts of the Andes will suffer if they become over-developed. There is a genuine fear that areas of Chile will suffer the cultural destruction witnessed in Mexico and European resorts. The policy of opening up Antarctica to tourism is also politically sensitive. Chile already has permanent settlements on the ice and many people see the decision to allow tourists there as a political move, enhancing Santiago"s territorial claim over part of Antarctica. The Chilean Government has promised to respect the environment as it seeks to bring tourism to these areas. But there are immense commercial pressures to exploit the country"s tourism potential. The Government will have to monitor developments closely if it is genuinely concerned in creating a balanced, controlled industry and if the price of an increasingly lucrative tourist market is not going to mean the loss of many of Chile"s natural riches.

单选题Avian influenza is an infectious disease of birds caused by type A strains of the influenza virus. The disease, which was first identified in Italy more than 100 years ago, occurs worldwide.All birds are thought to be susceptible to infection with avian influenza, though some species are more resistant to infection than others. Infection causes a wide spectrum of symptoms in birds, ranging from mild illness to a highly contagious and rapidly fatal disease resulting in severe epidemics. The latter is known as "highly pathogenic avian influenza". This form is characterized by sudden onset, severe illness, and rapid death, with a mortality that can approach 100%. Fifteen subtypes of influenza virus are known to infect birds, thus providing an extensive reservoir of influenza viruses potentially circulating in bird population. To date, all outbreaks of the highly pathogenic form have been caused by influenza A viruses of subtypes H5 and H7. Migratory waterfowl—most notably wild ducks—are the natural reservoir of avian influenza viruses, and these birds are also the most resistant to infection. Domestic poultry, including chickens and turkeys, are particularly susceptible to epidemics of rapidly fatal influenza. Direct or indirect contact of domestic flocks with wild migratory waterfowl has been implicated as a frequent cause of epidemics. Live bird markets have also played an important role in the spread of epidemics. Recent research has shown that viruses of low pathogenicity can, after circulation for sometimes short periods in a poultry population, mutate into highly pathogenic viruses. During a 1983-1984 epidemic in the United States of America, the H5N2 virus initially caused low mortality, but within six months became highly pathogenic, with a mortality approaching 90%. Control of the outbreak required destruction of more than 17 million birds at a cost of nearly US $65 million. During a 1999-2001 epidemic in Italy, the H7N1 virus, initially of low pathogenicity, mutated within 9 months to a highly pathogenic form. More than 13 million birds died or were destroyed. The quarantining of infected farms and destruction of infected or potentially exposed flocks are standard control measures aimed at preventing spread to other farms and eventual establishment of the virus in a country's poultry population. Apart from being highly contagious, avian influenza viruses are readily transmitted from farm to farm by mechanical means, such as by contaminated equipment, vehicles, feed, cages, or clothing. Highly pathogenic viruses can survive for long periods in the environment, especially when temperatures are low. Stringent sanitary measures on farms can, however, confer some degree of protection. In the absence of prompt control measures backed by good surveillance, epidemics can last for years. For example, an epidemic of H5N2 avian influenza, which began in Mexico in 1992, started with low pathogenicity, evolved to the highly fatal form, and was not controlled until 1995.

单选题I" m in the unusual position of being both a computer scientist and a professional musician. On the computer side, I" m best known for my work in virtual reality, a term I coined in the early 1980s. As a musician I write, perform, and record my own work. Canons for Wroclaw, a concerto I created for virtual instruments, was performed last December by the Chamber Orchestra of Wroclaw, Poland. All of this means that I have a few deeply felt ideas about Napster, the free software millions of people use to share their music collections over the Internet. Big media companies see Napster as theft because they can" t collect royalties when people use it. So they have asked the courts to kill it. As I write this, a settlement seems to be emerging. Napster will probably begin to charge for its services and pay royalties to at least some record companies. Whatever happens, the legal decisions surrounding Napster are important for reasons that transcend the music business and extend to our basic concepts of what it means to be free in a democracy. I believe the anti-Napster forces have failed to foresee dangerous implications of their course of action. They aren" t thinking about the harsh logic at the core of this technology. They do not understand what I call the Law of the Excluded Digital Middle; Digital tools can be either open or closed but resist being anything in between. An open digital tool is one that can be used in unforeseen ways. A tool like e-mail, meant to send text, might also—surprisingly—be used to send music. A closed tool is one in which there are technical restrictions that prevent unforeseen uses. The advantage of open tools is that more people can create new things with them; consequently, they tend to be more innovative. Closed tools are usually created because it is thought they will be more profitable; An owner can control them well enough to enforce bill collection. Of course, the open software movement energetically promotes the idea that innovation ends up generating more money than control does.

单选题Neuroscientists now understand at least some of the physiology behind a wide range of unconscious states, from deep sleep to coma, from partially conscious conditions to a persistent vegetative state, the condition diagnosed in Ms. Schiavo. New research, by laboratories in New York and Europe, has allowed for much clearer distinctions to be made between the uncounted number of people who at some time become comatose, the 10,000 to 15,000 Americans who subsist in vegetative states and the estimated 100,000 or more who exist in states of partial consciousness. This emerging picture should make it easier for doctors to judge which brain-damaged patients have some hope of recovering awareness, experts say, and already it is providing clues to the specific brain processes that sustain conscious awareness. "Understanding what these processes are will give us a better sense of how to help the whole range of people living with brain injuries," said Dr. Nicholas Schiff, an assistant professor of neurology and neuroscience at New York-Presbyterian/ Weill Cornell hospital. "That is where this field is ultimately headed: toward a better understanding of what consciousness is." The most familiar unconscious state is sleep, which in its deepest phases is characterized by little electrical activity in the brain and almost complete unresponsiveness. Coma, the most widely known state of impaired unconsciousness, is in fact a continuum. Doctors rate the extent to which a comatose person shows pain responses and reactions to verbal sounds on a scale from 3, for no response, to 13, for consistent responses. As in sleep, people in comas may move or make sounds and typically have no memory of either. But they almost always emerge from this state in two to three weeks, doctors say, when the eyes open spontaneously. What follows is critical for the person"s recovery. Those who are lucky, or who have less severe injuries, gradually awaken. "The first thing I remember was telling my ex-boyfriend, who was at the foot of the bed, to shut up," said Trisha Meili, who fell into a coma after being beaten and raped in 1990, and wrote about the experience in the book, I Am the Central Park Jogger. In the days after this memory, Ms. Meili said, she slipped in and out of conscious awareness, "as if my body was taking care of the most important things first, and leaving my moment to moment awareness for last." In fact, researchers say, this is precisely what happens. The primitive brain stem, which controls sleep-wake cycles as well as reflexes, asserts itself first, as the eyes open. Ideally, areas of the cerebral cortex, the seat of conscious thought, soon follow, like lights flicking on in the upper rooms of a darkened house. But in some cases—Ms. Schiavo"s was one of them—the cortical areas fail to engage, and the patient"s prognosis becomes dire. Neurologists were all but unanimous in diagnosing the condition of Ms. Schiavo, whose heart stopped temporarily in 1990, depriving her brain of oxygen. Brain cells and neural connections wither and die without oxygen, like marine life in a drained lake, leaving virtually nothing unharmed. People with these kinds of injuries—Nancy Cruzan, whose case reached the Supreme Court in 1990 is an example—almost always remain unresponsive if they have not regained awareness in the first months after the injury. In medical terms, they become persistently vegetative, a diagnosis first described in 1972 by Dr. Fred Plum of Cornell University and Dr. Bryan Jennett, a neurosurgeon at Glasgow University in Scotland. In a sense, the description of the diagnosis began the modern study of disorders of consciousness. "Before 1972 people talked about permanent comas, or irrecoverable comas, but we defined a different state altogether, with the eyes open, some reflex activity, but no sign of meaningful psychological responsiveness," Dr. Jennett, now a professor emeritus, said in an interview. In an exhaustive review of the medical histories of more than 700 persistently vegetative patients, a team of doctors in 1994 reported that about 15 percent of those who suffered brain damage from oxygen deprivation, like Ms. Schiavo, recovered some awareness within three months. After that, however, very few recovered and none did so after two years. About 52 percent of people with traumatic wounds to the head, often from car accidents, recovered some awareness in the first year after the injury, the study found; very few recovered after that. "It"s the difference between taking a blow to the brain, which affects a local area—and taking this global, whole-brain hit," said Dr. Joseph Fins, chief of the medical ethics division of New York-Presbyterian / Weill Cornell hospital. Yet these statistics cannot explain the stories of remarkable recovery that surfaced during the debate over Ms. Schiavo"s fate. There was Terry Wallis, a mechanic in Arkansas who regained awareness in 2003, more than 18 years after he fell into unconsciousness from a car accident; Sarah Scantlin, a Kansas woman who, also a victim of a car accident, emerged from a similar state after 19 years; and several others, whose collective human spirit seemed to defy the experts, and trump science. Researchers say these cases can be accounted for by recent studies that indicate the existence of yet another state of subdued responsiveness, one that represents a clear break from the vegetative.

单选题Technically, any substance other than food that alters our bodily or mental functioning is a drug. Many people mistakenly believe the term drug refers only to some sort of medicine or an illegal chemical taken by drug addicts. They don't realize that familiar substances such as alcohol and tobacco are also drugs. This is why the more neutral term substance is now used by many physicians and psychologists. The phrase substance abuse is often used instead of drug abuse to make clear that substances such as alcohol and tobacco can be just as harmfully misused as heroin and cocaine. We live in a society in which the medicinal and social use of substances (drugs) is pervasive: an aspirin to quiet a headache, some wine to be sociable, coffee to get going in the morning, a cigarette for the nerves. When do these socially acceptable and apparently constructive uses of a substance become misuses? First of all, most substances taken in excess will produce negative effects such as poisoning or intense perceptual distortions. Repeated use of a substance can also lead to physical addiction or substance dependence. Dependence is marked first by an increased tolerance, with more and more of the substance required to produce the desired effect, and then by the appearance of unpleasant withdrawal symptoms when the substance is discontinued. Drugs (substances) that affect the central nervous system and alter perception, mood, and behavior are known as psychoactive substances. Psychoactive substances are commonly grouped according to whether they are stimulants, depressants, or hallucinogens. Stimulants initially speed up or activate the central nervous system, whereas depressants slow it down. Hallucinogens have their primary effect on perception, distorting and altering it in a variety of ways including producing hallucinations. These are the substances often called psychedelic (from the Greek word meaning mind-manifestation) because they seemed to radically alter one's state of consciousness.

单选题Whitening the world's roofs would offset the emissions of the world's cars for 20 years, according to a new study from Lawrence Berkeley National Laboratory. Overall, installing lighter-colored roofs and pavements can cancel the heat effect of two years of global carbon dioxide emissions, Berkeley Lab says. It's the first roof-cooling study to use a global model to examine the issue. Lightening up roofs and pavement can offset 57 billion metric tons of carbon dioxide, about double the amount the world emitted in 2006, the study found. It was published in the journal Environmental Research Letters. Researchers used a conservative estimate of increased albedo, or solar reflection, suggesting that purely white roofs would be even better. They increased the albedo of all roof by 0. 25 and pavement by 0. 15. That means a black roof, which has an albedo of zero, would only need to be replaced by a roof of a cooler color — which might be more feasible to implement than a snowy white roof. Berkeley Lab says. The researchers extrapolated a roof's CO 2 offset over its average lifespan. If all roofs were converted to white or cool colors, they would offset about 24 gigatons (24 billion metric tons) of CO 2 , but only once. But assuming roofs last about 20 years, the researchers came up with 1. 2 gigatons per year. That equates to offsetting the emissions of roughly 300 million cars, all the in the world, for 20 years. Pavements and roofs cover 50 to 65 percent of urban areas and cause a heat-island effect because they absorb so much heat. That's why cities are significantly warmer than surrounding rural areas. This effect makes it harder—and therefore more expensive — to keep buildings cool in the summer. Winds also move the heat into the atmosphere, causing a regional warming effect. Energy secretary Steven Chu, a Nobel Laureate in physics (and former Berkeley Lab director), has advocated white roofs for years. He put his words into actions by directing all Energy Department offices to install white roofs. All newly installed roofs will be white, and black roofs might be replaced when it is cost-effective over the lifetime of the roof. "Cool roofs are one of the quickest and lowest-cost ways we can reduce our global carbon emissions and begin the hard work of slowing climate change. " He said in a statement.

单选题Whether the cause is maternal anti-bodies, heavy metals or something else, there is no question that the brains of young children with autism have unusual features. To begin with, they tend to be too big. In studies based on magnetic resonance imaging(MRI)and basic tape-measure readings , neuroscientist Eric Courchesne at Children" s Hospital of San Diego showed that while children with autism are born with ordinary-size brains, they experience a rapid expansion by age 2—particularly in the frontal lobes. By age 4, says Courchesne, autistic children tend to have brains the size of a normal 13-year-old. More recent studies by Admiral and others have found that the amygdale, an area associated with social behavior, is also oversize, a finding Admiral believes is related to the high levels of anxiety seen in as many as 80% of people with autism. Harvard pediatric neurologist Dr. Martha Herbert reported last year that the excess white matter in autistic brains has a specific distribution; local areas tend to be over connected, while links between more distant regions of the brain are weak. The brain" s right and left hemispheres are also poorly connected. It" s as if there are too many competing local services but no long distance. This observation jibes neady with imagining studies that look at live brain activity in autistic people. Studies using functional MRI show a lack of coordination among brain regions, says Marcel Just, director of Carnegie Mellon" s Center for Cognitive Brain Imaging in Pittsburgh, Pa. Just has scanned dozens of 15-to-35-year-old autistic people with IQs in the normal range, giving them thinking tasks as he monitors their brain activity. " One thing you see," says Just, " is that activity in different areas is not going up and down at the same time. There" s a lack of synchronization, sort of like a difference between a jam session and a string quartet. In autism, each area does its own thing. " What remains unclear is whether the interconnectivity problem is the result of autism or its cause. "It" s impossible to tell the chicken from the egg at this point," Just says. Autistic people have been shown to use their brains in unusual ways; they memorize alphabet characters in apart of the brain that ordinarily processes shapes. They tend to use the visual centers in the back of the brain for tasks usually handled by the prefrontal cortex. They often look at the mouth instead of the eyes of someone who is speaking. Their focus, says psychologist Ami Klin of Yale" s Child Study Center, is " not on the social allegiances—for example, the longing gaze of a mother—but physical allegiances—a mouth that moves. "

单选题Beyond the basic animal instincts to seek food and avoid pain, Freud identified two sources of psychic energy, which he called "drives": aggression and libido. The key to his theory is that these were unconscious drives, shaping our behavior without the mediation of our waking minds; they surface, heavily disguised, only in our dreams. The work of the past half-century in psychology and neuroscience has been to downplay the role of unconscious universal drives, focusing instead on rational processes in conscious life. But researchers have found evidence that Freud's drives really do exist, and they have their roots in the limbic system, a primitive part of the brain that operates mostly below the horizon of consciousness. Now more commonly referred to as emotions, the modern suite of drives comprises five: rage, panic, separation distress, lust and a variation on libido sometimes called seeking. The seeking drive is proving a particularly fruitful subject for researchers. Although like the others it originates in the limbic system, it also involves parts of the forebrain, the seat of higher mental functions. In the 1980s, Jaak Panksepp, a neurobiologist at Bowling Green State University in Ohio, became interested in a place near the cortex known as the ventral tegmental area, which in humans lies just above the hairline. When Panksepp stimulated the corresponding region in a mouse, the animal would sniff the air and walk around, as though it were looking for something. Was it hungry? No. The mouse would walk right by a plate of food, or for that matter any other object Panksepp could think of. This brain tissue seemed to cause a general desire for something new. "What I was seeing, " he says, "was the urge to do stuff. " Panksepp called this seeking. To neuropsychologist Mark Solms of University College in London, that sounds very much like libido. "Freud needed some sort of general, appetitive desire to seek pleasure in the world of objects, " says Solms. "Panksepp discovered as a neuroscientist what Freud discovered psychologically. " Solms studied the same region of the brain for his work on dreams. Since the 1970s, neurologists have known that dreaming takes place during a particular form of sleep known as REM — rapid eye movement — which is associated with a primitive part of the brain known as the pons. Accordingly, they regarded dreaming as a low-level phenomenon of no great psychological interest. When Solms looked into it, though, it turned out that the key structure involved in dreaming was actually the ventral tegmental, the same structure that Panksepp had identified as the seat of the "seeking" emotion. Dreams, it seemed, originate with the libido—which is just what Freud had believed. Freud's psychological map may have been flawed in many ways, but it also happens to be the most coherent and, from the standpoint of individual experience, meaningful theory of the mind. "Freud should be placed in the same category as Darwin, who lived before the discovery of genes, " says Panksepp. "Freud gave us a vision of a mental apparatus. We need to talk about it, develop it, test it. " Perhaps it's not a matter of proving Freud wrong or right, but of finishing the job.

单选题On September 7, 2001, a 68-year-old woman in Strasbourg, France, had her gall bladder (胆囊) removed by-surgeons operating, via computer from New York. It was the first complete telesurgery procedure performed by surgeons nearly 4 000 miles away from their patient. In New York, Marescaux teamed up with surgeon Michel Gagner to perform the historic long-distance operation. A high-speed fiber-optic service provided by France Telecom made the connection between New York and Strasbourg. The two surgeons controlled the instruments using an advanced robotic surgical system, designed by Computer Motion Inc. that enabled the procedure to be minimally invasive. The patient was released from the hospital after about 48 hours and regained normal activity the following week. The high-speed fiber-optic connection between New York and France made it possible to overcome a key obstacle to telesurgery time delay. It was crucial that a continuous time delay of less than 200 milliseconds be maintained throughout the operation, between the surgeon' s movements in New York and the return video (from Strasbourg) on his screen. The delay problem includes video coding decoding and signal transmission time. France Telecom' s engineers achieved an average time delay of 150 milliseconds. " I felt as comfortable operating on my patient as if I had been in the room," says Marescaux. The successful collaboration (合作) among medicine, advanced technology, and telecomm unications is likely to have enormous implications for patient care and doctor training. Highly skilled surgeons may soon regularly perform especially difficult operations through long-distance procedures. The computer systems used to control surgical movement can also lead to a breakthrough in teaching surgical techniques to a new generation of physicians. More surgeons-in-training will have the opportunity to observe their teachers in action in telesurgery operating rooms around the world. Marescaux describes the success of the remotely performed surgical procedure as the beginning of a "third revolution" in surgery within the last decade. The first was the arrival of minimally invasive surgery, enabling procedures to be performed with guidance by a camera, meaning that the abdomen (腹部) and thorax (胸腔) do not have to be opened. The second was the introduction of computer-assisted surgery, where complicated software algorithms(计算法)enhance the safety of the surgeon's movements during a procedure, making them more accurate, while introducing the concept of distance between the surgeon and the patient. It was thus natural to imagine that this distance-currently several meters in the operating room could potentially be up to several thousand kilometers.

单选题When people are struck by lightening, they fall to the ground as though they were struck by a severe blow to the head. After the shock they may remain unconscious, become semiconscious or be conscious but confused and dazed, at least for a time. Flashes of light may continue passing before their eyes, and blindness and deafness may follow. The nervous system may be badly affected, causing paralysis, pain in the limbs and even hemorrhage. There will be burns where the lightening passed through the body, and like all electrical bunts, they are often deep and sever. All persons, especially campers and hunters, should know how to give first aid to someone who has been struck by lightening. Do not be afraid to touch the victim. You won"t get a shock. The lightening has already been grounded. Remember that speed is of the greatest importance in severe cases. The first thing to do is to loosen tight clothing about the throat and waist. Then clear the air passages of mucus(黏液)if present, and apply artificial respiration if necessary. Give mouth-mouth resuscitation if needed, or give oxygen if available. Many victims thought to be dead have been revived after treatment. Send someone for a doctor as soon as possible, but don"t leave the victim alone. If a doctor is not available, take the person to a hospital as soon as the person can be safely moved. Signs of shock are: pale, cold, sticky skin; weak, rapid pulse; shallow, irregular breathing or, in extreme cases, no breathing at all. To treat shock, you must keep the patient lying down with the head lower than the feet and cover him or her with a blanket but watch out for overheating. Giving a stimulating hot tea or coffee will help, but only if the patient is thoroughly conscious. After breathing has been restored and shock is treated, treat the burns. Apply some salve and cover them with a clean cloth or a sterile dressing. If conscious, the patient will be badly frightened, so do all you can to reassure. A little knowledge and a helping hand may save someone"s life.

单选题The men set off in silence. Pedro walked with his dog a few paces behind the boys. When neighbors saw them walking along in this formation they would say that Pedro looked like a veritable patron striding behind his peons. Yet there were mornings when Pedro talked to the boys in the course of their two-hour walk to the fields, giving advice or telling, what work had to be done. The boys, however, spoke only in answer to a question. Out of their father's earshot they would joke about their sweet hearts ox visits to the saloons of Cuahnahuac. But this morning they moved silently down the road. It was still barely light. All around them, just beyond the far edges of the fields, the blue-green slopes of the pine-covered mountains rose through the morning mist, Pedro and Ricardo were headed for the mountain slope cornfield which they had cleared the year before. This was communal land belonging to the municipality which consisted of seven villages; anyone could work it. New clearings had to be made every two or three years, for heavy rains washed the top soil away. To acquire new fields Pedro and his sons burned the brush and weeds, cut down young trees, and built new stone fences. The boys worked well; they had the largest mountain clearing in Azteca. But the crops could supply enough corn and beans for only three or four months. So Pedro had to try other means of earning a living as well—making rope from maguey fiber, selling plums, hiring out his sons as farm-hands. One thing he would not do to earn money was to make charcoal for sale, as so many of his neighbors did. This practice, he knew, was wasteful of the precious oak and pine forests and ultimately ruined land. He had been one of the leaders in the struggle for the preservation of the communal forest lands. So he made charcoal only once a year and only for the use of his family.

单选题Ask most people how they define the American Dream and chances are, they'll say, "Success." The dream of individual opportunity has been home in America since Europeans discovered a "new world" in the Western Hemisphere. Early immigrants like Hector St. Jean de Crevecoeur praised highly the freedom and opportunity to be found in this new land. His glowing descriptions of a classless society where anyone could attain success through honesty and hard work fired the imaginations of many European readers. In letters from an American Farmer (1782) he wrote, "We are all excited at the sprite of an industry which is unfettered and unrestrained, because each person works for himself... We have no princes, for whom we toil, starve, and bleed. We are the most perfect society now existing in the world." The promise of a land where "the rewards of a man's industry follow with equal steps the progress of his labor" drew poor immigrants from Europe and fueled national expansion into the western territories. Our national mythology is full of illustration of the American success story. There's Benjamin Franklin, the very model of the self-educated, self-made man, who rose from modest origins to become a well-known scientist, philosopher, and statesman. In the nineteenth century, Horatio Alger, a writer of fiction for young boys, became America's best-selling author with rags-to-riches tales. The notion of success haunts us—we spend million every year reading about the rich and famous, learning how to" make a fortune in real estate with no money down", and " dressing for success". The myth of success has even invaded our personal relationships—today it's as important to be "successful" in marriage or parenthoods as it is to come out on top in business. But dreams easily turn into nightmares. Every American who hopes to "make it" also knows the fear of failure, because the myth of success inevitably implies comparison between the haves and the have-nots, the stars and the anonymous crowd. Under pressure of the myth, we become indulged in status symbols: we try to live in the "right" neighborhoods, wear the "right" clothes, and eat the "right" foods. These symbols of distinction assure us and others that we believe strongly in the fundamental equality of all, yet strive as hard as we can to separate ourselves from our fellow citizens.

单选题Breast cancer is second only to skin cancer as the most common malignancy diagnosed in women in the United States. In 2001, about 192 200 new cases of invasive breast cancer were diagnosed and 40 200 women died of the disease. Only lung cancer accounts for more cancer deaths in women. The incidence of breast cancer has increased over the last 20 years. Although some of the increase can be attributed to changes in reproductive patterns, such as delayed childbearing and having fewer children, much of the rise is due to the increased detection of smaller, earlier-stage cancers with the widespread adoption of mammography screening in asymptomatic women. According to data from the Surveillance, Epidemiology, and End Results Program, incidence rates of tumors less than 2.0 cm in diameter more than doubled from 1980 to 1987, whereas rates of tumors greater than 3.0 cm decreased by 27%. In particular, incidence rates of in situ breast cancer have risen dramatically over the last 25 years. The annual increase in age-adjusted ductal carcinoma in situ incidence rates from 1983 to 1992 was 17.5%. Although the incidence of breast cancer has been increasing, there has been a decline in breast cancer mortality. Death rates decreased 1.6% annually between 1989 and 1995, then 3.4% annually between 1995 and 1998. This improvement in the mortality rate has been attributed to both mammography screening and improvements in breast cancer treatment. Breast cancer has a number of identifiable risk factors. Aside from a personal history of breast cancer, the most important risk factor in women is age. Between 1994 and 1998, 77% of new cases of breast cancer and 84% of breast cancer deaths occurred in women older than 50 years. Other non-modifiable risk factors include family history, age at birth of the woman's first child, early menarche, and late menopause. Potentially modifiable risk factors include alcohol consumption, use of postmenopausal hormones, and obesity after menopause. Although most breast cancer cases are sporadic, up to 10% are linked to genetic predisposition. Women with a family history of breast cancer, especially in a first-degree relative (i. e, mother, sister, or daughter), have an increased risk of breast cancer. In general, a "positive family history" of breast cancer confers a relative risk of 2.0 to3.0, with the degree of risk varying directly with the closeness of the relationship. Paternal and maternal relatives with breast cancer contribute similarly to the increased risk. Most women with a family history of breast cancer do not have a history striking enough to suggest the presence of an inherited breast cancer syndrome. In many cases, primary care physicians can readily distinguish between families with heritable cancers and those with several sporadic cases. Women at high risk of inherited breast cancers typically have several relatives with breast cancer diagnosed before age 45 to 50 and may also have a family history of bilateral breast cancer, ovarian cancer, or male breast cancer.

单选题The one accident situation where immediate action must be taken is when a person stops breathing. This might be the result of drowning, electrocution, suffocation, head injury caused by a fall, poisoning or a variety of other accidents. If someone has stopped breathing, however, there may be a simpler cause; the breathing passages may be blocked by food, vomit, saliva or even the tongue. Whatever the cause, it is imperative that breathing is restarted quickly, as otherwise brain damage may result. Act quickly: lay the casualty flat on his back, and pull back the head while holding the jaws clenched. This prevents the tongue from falling back into the throat and blocking the air passages. If any foreign matter like sand or vomit can be seen in the victim" s mouth or throat, scoop it out with the fingers. False teeth are a particular hazard and often fall back into the throat of an unconscious person. If breathing does not start immediately, you must begin artificial respiration right away, by breathing directly into the casualty" s lungs through the mouth or nose. . . As you exhale deeply through the casualty" s nose, it is necessary to hold their mouth firmly closed. If you are breathing into the mouth, however, pinch the nostrils to stop the escape of air. If the airways are not obstructed you will see the chest of the casualty" s lungs. Each time you blow, turn your head to check that there is this regular rise and fall of the chest. This must be continued until breathing starts spontaneously, or in any event for at least an hour. As soon as the casualty starts to respond you should see an improvement in his colour, usually after the first dozen or so inflations. When breathing starts, it will be weak and shallow, and will still need assisting. Time your breaths to coincide with those of the casualty, as his breathing gradually strengthens. When breathing has restarted and can continue without help, the casualty will still be unconscious. He should be turned into the "unconscious" position, preferably with the body slightly higher than the head, and watched carefully to make sure that breathing continues. Don" t rush to get him to hospital. It is more important to make sure that breathing is strong and will continue while the casualty is being moved.

单选题Auctions are public sales of goods, conducted by an officially approved auctioneer. He asked the crowd to gather in the auction room to bid for various items on sale. He encourages buyers to bid higher figures and finally names the highest bidder as the buyer of the goods. This is called "knocking down" the goods, for the bidding ends when the auctioneer bangs a small hammer on a raised platform. The ancient Romans probably invented sales by auction and the English word comes from the Latin "autic", meaning "increase". The Romans usually sold in this way the spoils taken in war; these sales were called "sub hasta", meaning "under the spear", a spear being stuck in the ground as a signal for a crowd to gather. In England in the eighteenth and nineteenth centuries goods were often sold "by the candle"; a short candle was lit by the auctioneer and bids could be made while it was burning. Practically all goods can be sold by auction. Among these are coffee, skins, wool, tea, cocoa, furs, fruit, vegetables and wines. Auction sales are also usual for land and property, antique furniture, pictures, rare books, old china and works of art. The auction rooms at Chritie"s and Sotheby"s in London and New York are world famous. An auction is usually advertised beforehand with full particulars of the articles to be sold and where and when they can be viewed by the buyers. If the advertisement cannot give full details, catalogues are printed, and each group of goods to be sold together, called a "lot", is usually given a number. The auctioneer need not begin with lot one and continue the numerical order; he may wait until he notices the fact that certain buyers are in the room and then produce the lots they are likely to be interested in. The auctioneer"s services are paid for in the form of a percentage of the price the goods are sold for. The auctioneer therefore has a direct interest in pushing up the bidding.

单选题For the past several years, the Sunday newspaper supplement Parade has featured a column called "Ask Marilyn." People are invited to query Marilyn vos Savant, who at age 10 had tested at a mental level of someone about 23 years old; that gave her an IQ of 228-the highest score ever recorded. IQ tests ask you to complete verbal and visual analogies, to envision paper after it has been folded and cut, and to deduce numerical sequences, among other similar tasks. So it is a bit confusing when vos Savant fields such queries from the average Joe(whose IQ is 100)as, What"s the difference between love and fondness? Or what is the nature of luck and coincidence? It"s not obvious how the capacity to visualize objects and to figure out numerical patterns suits one to answer questions that have eluded some of the best poets and philosophers. Clearly, intelligence encompasses more than a score on a test. Just what does it mean to be smart? How much of intelligence can be specified, and how much can we learn about it from neurology, genetics, computer science and other fields? The defining term of intelligence in humans still seems to be the IQ score, even though IQ tests are not given as often as they used to be. The test comes primarily in two forms: the Stanford-Binet Intelligence Scale and the Wechsler Intelligence Scales(both come in adult and children"s version). Generally costing several hundred dollars, they are usually given only by psychologists, although variations of them populate bookstores and the World Wide Web. Superhigh scores like Vos Savant"s are no longer possible, because scoring is now based on a statistical population distribution among age peers, rather than simply dividing the mental age by the chronological age and multiplying by 100. Other standardized tests, such as the Scholastic Assessment Test(SAT)and the Graduate Record Exam(GRE), capture the main aspects of IQ tests. Such standardized tests may not assess all the important elements necessary to succeed in school and in life, argues Robert J. Sternberg. In his article "How Intelligent Is Intelligence Testing?" Sternberg notes that traditional test best assess analytical and verbal skills but fail to measure creativity and practical knowledge, components also critical to problem solving and life success. Moreover, IQ test do not necessarily predict so well once populations or situations change. Research has found that IQ predicted leadership skills when the tests were given under low-stress conditions, but under high-stress conditions, IQ was negatively correlated with leadership-that is, it predicted the opposite. Anyone who has toiled through SAT will testify that test-taking skill also matters, whether it knows when to guess or what questions to skip.