单选题Richard Satava, program manager for advanced medical technologies, has been a driving force in bringing virtual reality to medicine, where computers create a "virtual" or simulated environment for surgeons and other medical practitioners. "With virtual reality we'll be able to put a surgeon in every trench," said Satava. He envisaged a time when soldiers who are wounded fighting overseas are put in mobile surgical units equipped with computers. The computers would transmit images of the soldiers to surgeons back in the U. S.. The surgeons would look at the soldiers through virtual reality helmets that contain a small screen displaying the image of the wound. The doctors would guide robotic instruments in the battlefield mobile surgical unit that operate on the soldier. Although Satava's vision may be years away from standard operating procedure, scientists are progressing toward virtual reality surgery. Engineers at an international organization in California are developing a tele-operating device. As surgeons watch a three-dimensional image of the surgery, they move instruments that are connected to a computer, which passes their movements to the robotic instruments that perform the surgery. The computer provides feedback to the surgeon on force, textures, and sound. These technological wonders may not yet be part of the community hospital setting but increasingly some of the machinery is finding its way into civilian medicine. At Wayne State University Medical School, surgeon Lucia Zamorano takes images of the brain from computerized scans and uses a computer program to produce a 3D image. She can then maneuver the 3D image on the computer screen to map the shortest, least invasive surgical path to the tumor. Zamorano is also using technology that attaches a probe to surgical instruments so that she can track their positions. While cutting away a tumor deep in the brain, she watches the movement of her surgical tools in a computer graphics image of the patient's brain taken before surgery. During these procedures—operations that are done through small cuts in the body in which a miniature camera and surgical tools are maneuvered—surgeons are wearing 3D glasses for a better view. And they are commanding robot surgeons to cut away tissues more accurately than human surgeons can. Satava says, "We are in the midst of a fundamental change in the field of medicine."

单选题Every day, over a million people log onto different Internet-based games. There is truly something for everyone in the gaming world. Gaines provide a quick escape from【C1】______.Game developers are the new breed of storytellers, creating alternative【C2】______Games represent the ultimate interactive movie, allowing the user to control the direction of the plot. And now the newest technologies allow you to play games no matter where you are. At home, we have PC or video game consoles.【C3】______, a desktop or laptop computer can be loaded with OS-bundled games or Web-based freebies. Even while traveling, there are many wireless computers, portable devices, wireless phones and PDAs【C4】______ Games are now pushing back all the【C5】______once placed upon them by technology, category, realism, location and time. These advances are helping to push games into the【C6】______of virtual reality. Thus, the stuff of science fiction novels is gradually emerging, the graphic aspects of the game quickly【C7】______Initially, electronic games involved【C8】______moving blocks, across a TV or computer screen.【C9】______the vast increases in processing power, games are quickly approaching three-dimensional realism. This power allows a developer to create a【C10】______world where a gamer can look around in full 360-degree vision.

单选题The brain is organized into different regions, each responsible for different functions and in humans this organization is very marked. The largest parts of the brain are the cerebral hemispheres, which occupy most of the interior of the skull. They are layered structures, the most complex being the outer layer, known as the cerebral cortex, where the nerve cells are extremely densely packed to allow great intercon-nectivity. Its function is not fully understood, but we can get some indication of its purpose from studies of animals that have had it removed. A dog, for example, can still move in a coordinated manner, will eat and sleep, and even bark if it is disturbed. However, it also becomes blind and loses its sense smell— more significantly, perhaps, it loses all interest in its environment, not responding to people or to its name, nor to other dogs, even of the opposite sex. It also loses all ability to learn. In effect, it loses the characteristics that we generally refer to as indicating intelligence—awareness, interest and interaction with an environment, and an ability to adapt and learn. Thus the cerebral cortex seems to be the seat of the higher order functions of the brain, and the core of intelligence. The cerebral cortex has been the subject of investigation by researchers for many years, and is slowly revealing its secrets. It demonstrates a localization of functions, in that different areas of the cortex fulfill different functions, such as motion control, hearing, and vision. The visual part of the cortex is especially interesting. In the visual cortex, electrical stimulation of the cells can produce the sensation of light, and detailed analysis has shown that specific layers of neurons are sensitive to particular orientations of input stimuli, so that one layer responds maximally to horizontal lines, while another responds to vertical ones. Although much of this structure is genetically pre-determined, the orientation-specific layout of the cells appears to be learnt at an early stage. Animals brought up in an environment of purely horizontal lines do not develop neuron structures that respond to vertical orientations, showing that these structures are developed due to environmental input and not purely from genetic pre-determination. This is called self-organization of the visual cortex since there is no external teacher to guide the development of these structures.

单选题The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, but this is largely because,【C1】______animals, we stand upright. This means that our noses are【C2】______to perceiving those smells which float through the air, missing the majority of smells which stick to surfaces. In fact, though, we are extremely sensitive to smells, even if we do not generally realize it. Our noses are capable of【C3】______human smells even when these are【C4】______to far below one part in one million. Strangely, some people find that they can smell one type of flower but not another, whereas others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate【C5】______smell receptors in the nose. These receptors are the cells which sense smells and send【C6】______to the brain. However, it has been found that even people insensitive to a certain smell at first can suddenly become sensitive to it when【C7】______to it often enough. The explanation for insensitivity to smell seems to be that brain finds it inefficient to keep all smell receptors working all the time but can【C8】______new receptors if necessary. This may also explain why we are not usually sensitive to our own smells we simply do not need to be. We are not【C9】______of the usual smell of our own house but we notice new smells when we visit someone else's. The brain finds it best to keep smell receptors【C10】______for unfamiliar and emergency signals such as the smell of smoke, which might indicate the danger of fire.

单选题During the past 30 years or so, health care has increasingly become a form of business. In addition, the environment surrounding health care has been greatly altered by the advent of more sophisticated medical technologies and increased specialization. It is no longer true to say that doctors regard their profession as a sacred calling, and while the doctor-patient relationship still remains, it is not the relationship based solely on trust which it used to be. Of course there are many doctors who have endeavored to increase the transparency of their behavior as medical professionals, and patients can receive effective treatment when such doctors work closely together and share notes. An example of such cooperation can be found in the field of remote health care, which has been introduced on an experimental basis in several regions. Since most medical specialists live in cities, patients who live in the country have to travel a long distance to consult a specialist. This is especially hard on the elderly, both financially and physically. Through a computer network, patients who live in the country can consult a medical specialist in the city, tell him their symptoms, and receive advice without the need for a journey to the specialist's office. Also, with several doctors being assigned to a single patient, the transparency of each doctor's behavior is further ensured. On the other hand, however, it is also true that remote health consultation is not generally regarded as a form of medical treatment. For any sort of consultation to be regarded as medical treatment, most people feel that the patient must actually visit the doctor, and undergo an examination by the doctor in person. Remote health care is essentially a means for doctors to work as a team. In order for this to be practicable, it is important to establish a system whereby financial support can be extended to a doctor who as a member of a medical team provides only information. Establishment of such a system will further advance the cause of "free access to information" in the health care field.

单选题Where one stage of child development has been left out, or not sufficiently experienced, the child may have to go back and capture the experience of it. A good home makes this possible, for example by providing the opportunity for the child to play with a clockwork car or toy railway train up to any age if he still needs to do so. This principle, in fact, underlies all psychological treatment of children in difficulties with their development, and is the basis of work in child clinics. The beginnings of discipline are in the nursery. Even the youngest baby is taught by gradual stages to wait for food, to sleep and wake at regular intervals and so on. If the child feels the world around him is a warm and friendly one, he slowly accepts its rhythm and accustoms himself to conforming to its demands. Learning to wait for things, particularly for food, is a very important element in upbringing, and is achieved successfully only if too great demands are not made before the child can understand them. Every parent watches eagerly the child's acquisition of each new skill—the first spoken words, the first independent steps, or the beginning of reading and writing. It is often tempting to hurry the child beyond his natural learning rate, but this can set up dangerous feeling of failure and states of anxiety in the child. This might happen at any stage. A baby might be forced to use a toilet too early, a young child might be encouraged to learn to read before he knows the meaning of the words he reads. On the other hand, though, if a child is left alone too much, or without any learning opportunities, he loses his natural zest for life and his desire to find out new things for himself. Learning together is a fruit source of relationship between children and parents. By playing together, parents learn more about their children and children learn more from their parents. Toys and games which both parents and children can share are an important means of achieving this co-operation. Building-block toys, jigsaw puzzles and crossword are good examples. Parents vary greatly in their degree of strictness or indulgence towards their children. Some may be especially strict in money matters, others are severe over times of coming home at night, punctuality for meals or personal cleanliness. In general, the controls imposed represent the needs of the parents and the values of the community as much as the child's own happiness and well-being.

单选题Biotechnology is expected to bring important advances in medical diagnosis and therapy, in solving food problems, in energy saving, in environmentally compatible industrial and agricultural production, and in specially targeted environmental protection projects. Genetically altered microorganisms can break down a wide range of pollutants by being used, for example, in bio-filters and wastewater-treatment facilities, and in the clean-up of polluted sites. Genetically modified organisms can also alleviate environmental burdens by reducing the need for pesticides, fertilizers, and medications. Sustainability, as a strategic aim, involves optimizing the interactions between nature, society, and the economy, in accordance with ecological criteria. Political leaders and scientists alike face the challenge of recognizing interrelationships and interactions between ecological, economic and social factors and taking account of these factors when seeking solution strategies. To meet this challenge , decision-makers require interdisciplinary approaches and strategies that cut across political lines. Environmental discussions must become more objective, and this includes, especially, debates about the risks of new technologies, which are often ideologically charged. In light of the complex issues involved in sustainable development, we need clearer standards for orienting and assessing our environmental policies. Sustainable development can succeed only if all areas of the political sector, of society, and of science accept the concept and work together to implement it. A common basic understanding of environmental ethics is needed to ensure that protection of the natural foundation of life becomes a major consideration in all political and individual action. A dialogue among representatives of all sectors of society is needed if appropriate environmental policies are to be devised and implemented.

单选题What we don"t know about kids and television could fill a weeklong miniseries. Given worries about everything from childhood obesity to scholastic shortcomings, it"s high time to find out. But before Congress approves $20 million a year to research children and the media, it should get more specific assurances that the money will pay for comprehensive, high-quality studies instead of bits of teasing information. Up to now, a patchwork of research on kids and TV has yielded plenty of suspicion but little real knowledge. Yes, a study two years ago found that teenagers who watched a lot of TV tended to be more aggressive. But what does that mean? Maybe more-aggressive kids are drawn more to TV. Ditto for the April study about preschoolers who watch hours of TV tending to have attention-span problems later on. It"s possible that children with a propensity toward attention problems are drawn more to that jumpy on-screen world in the first place. For better or worse, U.S. kids spend a lot of time in front of a TV or computer screen, two hours daily for those 5 and younger. If the schools spent two hours a day on a single activity, there would be intense concern about its value. So there is worth in legislation by Sen. Joe Lieberman to provide $100 million over five years for research on child development and electronic media. A scientific panel would set up a list of the key issues to be studied and review grant applications from universities or nonprofit institutes. This centralized approach makes sense—especially considering the money involved. Good studies are costly, and there haven"t been enough of them on this subject. Merely showing a link between TV viewing and a certain behavior doesn"t prove anything. In addition to the possibility the behavior is causing the TV watching instead of the other way around, a third factor could be causing both. Only carefully controlled studies obtain worthwhile results. At their best, such studies might tell us whether educational computer games for toddlers interrupt the natural development of the brain instead of aiding it, or whether seeing Ronald McDonald cavort on a soccer field makes a child more active or just more likely to crave French fries. Parents could decide limits based on more than instinct. But before spending the money, Congress should insist on a quality of research that will give the public answers about TV instead of more arguments. This shouldn"t be a handout to think tanks for more mushy research on a complicated but vital issue.

单选题Researchers have recently found a connection between disease and stressful situations. To test this theory, psychologists are trying to find a link between the brain and the immune system. The immune system in our bodies fights the bacteria and viruses which cause disease. Therefore , whether or not we are likely to get various diseases depends on how well our immune system works. Biologists used to think that the immune system was a separate, independent part of our bodies. Recently, however, they have found that our brain can affect our immune system. This discovery indicates that there may be a connection between emotional factors, such as stress or depression, and illness. Although many doctors in the past suspected a connection between emotional factor and disease, they had no proof. Scientists have only recently discovered how the brain and the immune system function. Before this, no one could see a link between them. As a result, medical science never seriously considered the idea that psychological factors could cause disease. Several recent studies showed a connection between stress and illness, for example, researchers went to an American military school to study the students. They found that the sick students there had a lot of academic pressure and wanted to achieve, but they were not very good students. In a similar study, researchers studied a group of student nurses and found that the nurses who developed cold sores were the ones who described themselves as generally unhappy people. In addition to these results, which support their theory, researchers are also looking for proof that stress can damage the immune system. Researchers studied recently bereaved people, i. e. , people whose loved ones have just died, because they are more likely to become ill or die. By examining the immune system of recently bereaved people, the researchers made an important discovery. They examined some white blood cells which are an important part of the immune system. They were not functioning properly. The fact that they were not working correctly indicates that severe psychological stress, such as a loved one" s death, may damage an important part of our immune system. There is still no positive proof of a connection between the immune system and psychological factors. Researchers also say that the results of the studies on bereaved people could have a different explanation. For example, bereaved people often sleep and eat less than normal, or may drink alcohol or take medication. These factors can also affect the immune system. More research is needed to clearly establish the connection between the immune system and psychological factors.

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.