单选题 A Miracle Cancer Cure Unless you have gone through the experience yourself, or watched a loved one's struggle, you really have no idea just how desperate cancer can make you. You pray, you rage, you bargain with God, but most of all you clutch at any hope, no matter how remote, of a second chance at life. For a few excited days last week, however, it seemed as if the whole world was a cancer patient and that all humankind had been granted a reprieve. Triggered by a front-page medical news story in the usually reserved The New York Times, all anybody was talking about on the radio, on television, on the Internet, in phone calls to friends and relatives—was the report that a combination of two new drugs could, as The New York Times put it, cure cancer in two years. In a matter of hours patients had jammed their doctors' phone lines begging for a chance to test the miracle cancer cure. Cancer scientists raced to the phones and fax lines to make sure everyone knew about their research too, generating a new round of headlines. The time certainly seemed ripe for a breakthrough in cancer. Only last month scientists at the National Cancer Institute announced that they were halting a clinical trial of a drug called tamoxifen—and offering it to patients getting the placebo—because it had proved so effective at preventing breast cancer (although it also seemed to increase the risk of uterine cancer). Two weeks later came The New York Times' report that two new drugs can shrink tumors of every variety without any side effects whatsoever. It all seemed too good to be true, and of course it was. There are no miracle cancer drugs, at least not yet. At this stage all the drug manufacturer can offer is some very interesting molecules, and the only cancers they have cures so far have been in mice. By the middle of last week, even the most breathless TV talk-show hosts had learned what every scientist already knew: that curing a disease in lab animals is not the same as doing it in humans. "The history of cancer research has been a history of curing cancers in the mouse," Dr. Richard Klausner, head of the National Cancer Institute, told the Los Angles Times. "We have cured mice of cancer for decades—and it simply didn't work in people."

单选题The girl is Ugazina/U at herself in the mirror.

单选题Relieving the Pain "Exercise may be the best treatment of chronic pain," say doctors at a new clinic for dealing with pain. "People with chronic pain need to stop lying around, go out more, and start exercising." The instinctive reaction to acute pain is to stop moving and to try to protect the source of pain. But it seems that this is often not productive, especially in the case of back pain. Back pain, after headaches and tiredness, has become the third most common reason for people to visit their doctors. Painful backs now account for millions of days off work. Lumbar (腰部的) pains are partly the price humans pay for taking their forelimbs off the ground, but they are made worse by a sedentary (久坐不动的) lifestyle. Lack of exercise slowly decreases the flexibility and strength of muscles, so that it is more difficult to take pressure off the site of pain. Exercise is essential It releases endorphins (内啡肽), the body"s "feel-good" chemicals, which are natural painkillers. In fact, these are so important that researchers are now looking for drugs that can maintain a comfortable level of endorphins in the body. Most people who go to a family doctor complaining of pain are prescribed pain-killing drugs rather than exercise. Since finding the cause of backache is not so easy, doctors frequently do not know the precise cause of the discomfort, and as the pain continues, sufferers end up taking stronger doses or a series of different drugs. "It"s crazy," says Dr. Brasseur, a therapist at the International Association for the Study of Pain. "Some of them are taking different drugs prescribed by different doctors, I"ve just seen a patient who was taking two drugs which turned out to be the same thing under different names." A generation of new pain clinics now operates on the basis that drugs are best avoided. Once patients have undergone the initial physical and psychological check up, their medication is cut down as much as possible. Taking patients off drugs also prepares them for physical activity. In some pain-relief clinics, patients begin the day with muscle contraction and relaxation exercises, followed by an hour on exercise bikes. Later in the day, they practice tai chi (太极), self-defense, and deep thought. This compares with an average of two-and-a-half hours" physiotherapy (理疗) a week in a traditional hospital program. "The idea is to strengthen and to increase long-lasting energy, flexibility, and confidence," explains Bill Wiles, a consultant pain doctor in Liverpool. "Patients undergoing this therapy get back to work and resume healthy active lifestyles much sooner than those subjected to more conservative treatment."

单选题What Is Market? The word market is used in a number of ways. There is a stock market and an automobile market,a retail market for furniture and a wholesale market for furniture. One person may be going to the market:another may plan to market a product. What,then is a market? A market may be defined as a place where buyers and sellers meet, goods or services are offered for sale. and transfers of ownership occur. A market may also be defined as the demand made by a certain group of potential buyers for a good or service. For instance,there is a farm market for petroleum products. The terms market and demand are often used interchangeably; they may also be used jointly as market demand. These definitions are not sufficiently precise to be useful to us here. For business purposes we define a market as people or organizations with wants (needs) to satisfy,money to spend, and the willingness to spend it. Thus in the market demand for any given product or service, there are three factors to consider-people or organizations with wants(needs), their purchasing power,and their buying behavior. We shall employ the dictionary definition of needs:the lack of anything that is required, desired,or useful. We do not limit needs to the narrow physiological requirements of food, clothing and shelter essential for survival. In our discussion the words needs and wants are used synonymously and interchangeably. In a strict interpretation,however,needs would refer to such basic physiological requirements as food,clothing,and shelter, while wants would be non-basic preferences. However,in our affluent society,little is to be gained by trying to differentiate between the two. Many of us would see as needs some items that are far beyond food, clothing, and shelter.

单选题The Klondike was the {{U}}scene{{/U}} of one of the biggest gold rushes the world has ever known. A. location B. view C. event D. landscape

单选题 Souped-up(效力增强了的) enzymes that flush poisons out of cells more efficiently than their natural counterparts(对应的人或物) could alleviate some of the severe side effects of chemotherapy and so improve the chances of curing cancers. Many anticancer drugs attack tumor cells because they divide more rapidly than heathy cells. But some vital healthy cells also divide faster thanormal, and these are destroyed as well. The most vital cells caught in the chemical cross-fire are those made in the bone marrow(骨髓). Under normal circumstances, these mature into platelets(血小板), which are vital for wound-healing, and white blood cells that fight infections. If levels of these cells fall, patients become dangerously vulnerable to infection and can suffer such severe internal bleeding that treatment has to be stopped. Surviving cancer cells can then re-grow and reduce the effectiveness of the therapy. Bill Fehl and his colleagues at the University of Wisconsin Medical School have engineered an enzyme that could make bone marrow cells resistant to the cancer drugs, so higher doses can be given and side effects reduced. The idea is to take healthy bone marrow cells from patients before they begin chemotherapy, then equip these cells with the genes that make the enzyme drug-resistant. When returned to the patient, the improved bone marrow cells could then withstand heavy doses of the drugs. The natural version of the enzyme—called glutathione Stransferase(谷胱甘肽S转移酶) —is produced mainly in the liver and catalyses(催化) the breakdown of compounds that might otherwise damage DNA in cells. GST also neutralizes(中和) the toxic breakdown products of anticancer drugs, which makes it suitable for protecting bone marrow cells. But natural GST does not work efficiently enough to avoid being swamped by high doses of drugs. GST catalyses a reaction between potentially toxic compounds and glutathione—a peptide (肽) produced in almost all cells of the body. The GST molecule has a cavity, or "active site", where the two molecules are brought close enough to react. This neutralizes the toxin, which passes into the blood to be excreted in the patient's urine. Using machines for synthesizing(结合,使合成)DNA, Fehl and his colleagues made thousands of "scrambled" versions of the parts of the GST gene that make the active site of the enzyme. They inserted these scrambled genes into Escherichia coll. By exposing the bacteria to increasing quantities of the anticancer drug, mechlorethamine(氮芥), Fehl screened out the ones most tolerant to the drug. "By this method, we made enzymes 30 times as efficient as the natural one," says Fehl. In other words, it took 30 times as much drug to kill the bacteria. Fehl has already exposed mice carrying copies of the doctored gene to known carcinogens(致癌物) to see how efficient the gene is at mopping up the toxins. The more efficient it is, the less damage the toxins do and fewer tumors should appear. "We anticipate a significant reduction (in the number of cancers) in the group carrying the gene, "says Fehl, who is still analyzing the results. Fehl's team has applied for a patent covering the technique, and hopes to develop treatments with Systemix, a company based in Palo Alto, California. Brian Ketterer, who heads the Cancer Research Campaign's molecular toxicology group in London, says Fehl's work could be important. But he warns that the proposed strategy would not protect cells lining the gut from chemotherapy drugs.

单选题We must run, Uotherwise/U we will be late.

单选题Jack eventually overtook the last truck.

单选题Is ￡ 20 {{U}}sufficient{{/U}} for the expenses of your journey?

单选题He is determined to consolidate his power.

单选题 阅读下面这篇短文，短文后列出7个句子，请根据短文的内容对每个句子做出判断。 {{B}}Most Adults in US Have Low Risk of Heart Disease{{/B}} More than 80 percent of US adults have a less than 10-percent risk of developing heart disease in the next 10 years, according to a report in the Journal of the American College of Cardiology. Just 3 percent have a risk that exceeds 20 percent. "I hope that these numbers will give physicians, researchers, health policy analysts, and others a better idea of how coronary heart disease is distributed in the US population," lead author Dr. Earl S. Ford. from the Centers for Disease Control and Prevention in Atlanta, said in a statement. The findings are based on analysis of data from 13,769 subjects, between 20 and 79 years of age, who participated in the Third National Health and Nutrition Examination Survey from 1988 to 1994. Overall, 82 percent of adults had a risk of less than 10 percent, 15 percent had a risk that fell between 10 to 20 percent, and 3 percent had a risk above 20 percent. The proportion of subjects in the highest risk group increased with advancing age, and men were more likely than women to be in this group. By contrast, race or ethnicity had little effect on risk distributions. Although the report suggests that most adults have a low 10-year risk of heart disease, a large proportion have a high or immediate risk, Dr. Daniel S. Berman, from Cedars-Sinai Medical Center in Los Angeles, and Dr. Nathan D. Wong, from the University of California at Irvine, note in a related editorial. Aggressive treatment measures and public health strategies are needed to shift the overall population risk downward, they add.

单选题He Uconfesses/U that he has done it.

单选题It came as something of a surprise when Diana, Princess of Wales, made a trip to Angola in 1997, to support the Red Cross's campaign for a total ban on all anti-personnel landmines. Within hours of arriving in Angola, television screens around the world were filled with images of her comforting victims injured in explosions caused by landmines. "I knew the statistics," she said, "But putting a face to those figures brought the reality home to me: like when I met Sandra, a 13-year-old girl who had lost her leg, and people like her. " The Princess concluded with a simple message: "We must stop landmines. " And she used every opportunity during her visit to repeat this message. But, back in London, her views were not shared by some members of the British government, which refused to support a ban on these weapons. Angry politicians launched an attack on the Princess in the press. They described her as "very ill-informed" and a "loose cannon" (乱放炮的人). The Princess responded by brushing aside the criticisms: "This is a distraction (干扰) we do not need. All I'm trying to do is help. " Opposition parties, the media and the public immediately voiced their support for the Princess. To make matters worse for the government, it soon emerged that the Princess's trip had been approved by the Foreign Office, and that she was in fact very well-informed about both the situation in Angola and the British government's policy regarding landmines. The result was a severe embarrassment for the government. To try and limit the damage, the Foreign Secretary, Malcolm Rifkind, claimed that the Princess's views on landmines were not very different from government policy, and that it was "working towards" a worldwide ban. The Defense Secretary, Michael Portillo, claimed the matter was "a misinterpretation or misunderstanding. " For the Princess, the trip to this war torn country was an excellent opportunity to use her ,popularity to show the world how much destruction and suffering landmines can cause. She said that the experience had also given her the chance to get closer to people and their problems.

单选题What can be concluded from the second and third paragraphs?

单选题What are my chances of promotion if I stay here?

单选题Most Adults in US Have Low Risk of Heart Disease More than 80 percent of US adults have a less than 10-percent risk of developing heart disease in the next 10 years, according to a report in the Journal of the American College of Cardiology. Just 3 percent have a risk that exceeds 20 percent. "I hope that these numbers will give physicians, researchers, health policy analysts, and others a better idea of how coronary heart disease is distributed in the US population," lead author Dr. Earl S. Ford, from the Centers for Disease Control and Prevention in Atlanta, said in a statement. The findings are based on analysis of data from 13,769 subjects, between 20 and 79 years of age, who participated in the Third National Health and Nutrition Examination Survey from 1988 to 1994. Overall, 82 percent of adults had a risk of less than 10 percent, 15 percent had a risk that fell between 10 to 20 percent, and 3 percent had a risk above 20 percent. The proportion of subjects in the highest risk group increased with advancing age, and men were more likely than women to be in this group. By contrast, race or ethnicity had little effect on risk distributions. Although the report suggests that most adults have a low 10-year risk of heart disease, a large proportion have a high or immediate risk, Dr. Daniel S. Berman, from Cedars-Sinai Medical Center in Los Angeles, and Dr. Nathan D. Wong, from the University of California at Irvine, note in a related editorial. Aggressive treatment measures and public health strategies are needed to shift the overall population risk downward, they add.

单选题You'll be agreeably surprised by its {{U}}reasonable{{/U}} price.

单选题California Gives Green Light to Space Solar Power Energy beamed down from space is one step closer to reality, now that California has given the green light to an agreement that would see the Pacific Gas and Electric Company buy 200 megawatt (兆瓦) of power beamed down from solar-power satellites beginning in 2016. But some major challenges will have to be overcome if the technology is to be used widely. A start-up company called Solaren is designing the satellites, which it says will use radio waves to beam energy down to a receiving station on Earth. The attraction of collecting solar power in space is the almost uninterrupted sunshine available in geosynchronous (与地球同步的) orbit. Earth-based solar cells, by contrast, can only collect sun light during daytime and when skies are clear. But space-based solar power must grapple (努力克服) with the high cost per kilogram of launching things into space, says Richard Schwartz of Purdue University in West Lafayette, Indiana. "If you"re talking about it being economically viable or power of the Earth, it"s a tough go," he says. Cal Boer man, Solaren"s director of energy services, says the company designed its satellites with a view to keeping launch costs down. "We knew we had to come up with a different, revolutionary design," he says. A patent the company has won describes ways to reduce the system"s weight, including using inflatable mirrors to focus sunlight on solar cells, so a smaller number can collect the same amount of energy. But using mirrors introduces other challenges, including keeping the solar cells from overheating, says Schwartz. "You have to take care of heat dissipation (散发) because you"re now concentrating a lot of energy in one place," he says. According to the company"s patent, Solaren"s solar cells will be connected to radiators to help keep them cool. Though Boer man says the company believes it can make space-based solar power work, it is not expecting to crowd out other forms of renewable energy. Laws in California and other states require increasing use of renewable energy in coming years, he points out. "To meet those needs, we"re going to need all types of renewable energy sources," he says.

单选题These factors interact intimately and cannot be separated.

单选题 Between 1986 and 1992 in the United States, mortality due to coronary heart disease among white men 45 to 74 years of age decreased by 26 percent, continuing a trend that began in the mid-1960s. Americans are thus doing something right. But did fish consumption help? This is where the Health Professionals Follow-Up(起作用) Study comes in. The study deals with the intake(摄影) of n-3 fatty acids and fish. The researchers calculated the intake of fish for 44,895 male health professionals—most of them dentists—in 1986 and kept track of their health status for the next six years. Surprisingly, the intake of n-3 fatty acids or fish in 1986 was not related to the risk of subsequent coronary disease. The number of participants was much larger than in other studies, and the methods and data analysis were solid. Also, measurements of fatty acids in adipose tissue showed that the questionnaire reliably ranked respondents according to their intake of n3 fatty acids. The researchers carefully spell out the limitations of the study. First, two thirds of the men had greatly increased their intake of fish over the 10 years before 1986. Some of those increases could have occurred. Shortly before the base-line investigation in 1986, because the inverse relation between fish consumption and mortality due to coronary heart disease was first reported in 1985. Thus, data on fish intake may not reflect long term habits, and changes in fish intake during follow-up could also have attenuated an association with coronary disease. The authors performed separate analyses including only men who reported no change in their fish intake and again found no effect. However, it is hard for people to recall whether they changed their diet several years ago. Second, the fish intake of these educated men was high and was more comparable with that of Norwegians or Japanese than with intake in the U.S. men studied previously. The epidemiologic data suggest that any beneficial effect is obtained with one or two servings of fish per week and that more is not better. Moreover, previous studies of fish intake have shown an association with the rate of mortality due to coronary disease, rather than with the incidence of nonfatal coronaty disease or coronary surgery. When seen in that light, there is some agreement between the present study and previous reports, because the risk of death from coronariy heart disease was about 25 percent lower among men who ate at least some fish than among those who ate no fish at all. A third limitation of the study was that some of the men studied may have begun to eat fish, or may have eaten more, because they thought that they were at increased risk of a heart attack;the men in the highest 20 percent of the study group in terms of their in-take of n-3 fatty acids more frequently reported a family history of coronary disease or a personal history of high cholesterol levels than men who ate less fish. The Harvard investigators concluded that increasing fish intake beyond one or two servings per week is unlikely to reduce the risk of coronary events substantially in men who are initially free of coronary disease. This is a prudent conclusion, and it could be extended to fish-oil capsules, which provide n-3 fatty acids in much larger amounts than are commonly consumed in food. The findings of the Health Professionals Follow-up Study should somewhat dampen enthusiasm for fish and fish oil as a panacea against coronary disease. A little fish may still do some good, but more fish is not necessarily better.