单选题The doctors have abandoned the hope to rescue the old man.

单选题下面的短文后列出了7个句子，请根据短文的内容对每个句子做出判断：如果该句提供的是正确信息，请选择A；如果该句提供的是 错误信息，请选择B；如果该句的信息文中没有提及，请选择C。 Want to Be 100? Listen to These 5 Centenarians(百岁老人) Five neighbors at a central Missouri retirement community who are all centenarians get asked all the time: "How did you live to be 100?." If you want to live to 100 or more, this rare group of five golden girls says the key to longevity (长寿)is working hard at a job you love and taking care of your body while you're at it. Even though an estimated 70,000 people in the country are currently at the century mark or be yond in age, it is unusual to find five 100-year-olds living in one place. The average life-span(寿命) of Americans is about two or three years short of an 80th birthday party. And most people don't want to cut out coffee, soda, alcohol, cigarettes, and eat healthy food. "People tell me all the time, 'I don't want to live to be 100,'" said Mildred Leaver, who turned 100 in June. "I think that's just sad. Aging is attitude and I don't feel old," said Leaver, a former educator who still drives her Buick around town. It doesn't take long to see that Leaver and her neighbors Mildred Harris, Grace Wolfsan, Gladys Stuart and Viola Semas, have a lot more in common than their longevity and lifelong healthy habits. All are 100 except Stuart, who is 101. Even though their sight and hearing aren't what they used to be, they've all avoided illnesses that many elderly people are stricken with. It's been 50 years since Leaver beat cancer for the first and only time. The common thread that connects these women is the decades of service to jobs each loved as a farmer, designer, school principal, bookkeeper and secretary. In the early years of their lives, gain fully employed women like them were just as rare as 100-year-olds are today.

单选题Patience is one of the most important attributes in a teacher.

单选题Her sister urged her to apply for the job.

单选题2. Yoga and Health There are many ways to stay healthy and combat stress. Long before television was used to advertise ways to grow healthier there was Yoga to aid people in their desire to be healthier. People who practice Yoga will tell you to turn off the TV, grab something soft to sit on, and get ready to become healthier and say goodbye to stress. Some people describe Yoga as an ancient method of phyrsical and mental exercises that can be practiced anywhere. Unlike many other forms of exercise, Yoga does not require any gadgets (器械). People who use Yoga to grow healthier Call do so by simply wearing some comfortable clothes and using a blanket to do their training on. Yoga is practiced by all kinds of people. You do not have to be big or small, young or old, a great athlete or a non - athlete. You do not need balls, gloves, expensive shoes, or anything with wheels to practice Yoga. Everyone can practice it. You can also practice by yourself or with a group, indoors or out. Yoga teachers tell you that Yoga is a series of physical exercises that use the body and mind to create harmony and health within yourself Yoga allows you to gain strength, calmness, and flexibility while relieving stress and tension from your body. About 2000 years ago in India, a wise man, Pantanjali, outlined the system for Yoga. In his writings, he explains how Yoga tackles both physical and emotional ailments. Yoga not only can help you recover from a physical condition, such as a bad back, asthma, or high blood pressure, but it also can help those of us who suffer from anxiety or depression. Yoga can do what all those items you see on late night television claim to do, and you do not have to buy anything to get started. Yoga, by disciplining the body and the mind, provides you with a very sophisticated and effective way to curb the effects of stress. Today, as you worry about everything from grades to terrorism, stress can take its toll. Maybe you do not need to add stress by trying to decide which television product to buy to make you healthy. By practicing Yoga, stress is minimized, and you can get back to the business of getting and staying healthy. If you have not already done so, you might want to learn more about Yoga as a way to improve your health.

单选题While some bacteria are beneficial, others are {{U}}harmful{{/U}} in that cause disease.

单选题 Plant Gas Scientists have been studying natural sources of methane for decades but hadn't regarded plants as a producer, notes Frank Keppler, a geochemist at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. Now Keppler and his colleagues find that plants, from grasses to trees, may also be sources of the greenhouse gas. This is really surprising, because most scientists assumed that methane production requires an oxygen-free environment. Previously, researchers had thought that it was impossible for plants to make significant amounts of the gas. They had assumed that, microbes need to be in environments without oxygen to produce methane. Methane is a greenhouse gas, like carbon dioxide. Gases such as methane and carbon dioxide trap heat in Earth's atmosphere and contribute to global warming. In its experiments, Keppler's team used sealed chambers that contained the same concentration of oxygen that Earth's atmosphere has. They measured the amounts of methane that were released by both living plants; and dried plant material, such as fallen leaves. With the dried plants, the researchers took measurement at temperatures ranging from 30 degrees Celsius to 70 degrees Celsius. At 30 degrees Celsius, they found, a gram of dried plant material released up to 3 nanograms of methane per hour. (One nanogram is a billionth of a gram.) With every 10-degree rise in temperature, the amount of methane released each hour roughly doubled. Living plants growing at their normal temperatures released as much as 370 nanograms of methane per gram of plant tissue per hour. Methane emissions tripled when living and dead plant was exposed to sunlight. Because there was plenty of oxygen available, it's unlikely that the types of bacteria that normally make methane were involved. Experiments on plants that were grown in water rather than soil also resulted in methane emissions. That's another strong sign that the gas came from the plants and not soil microbes. The new finding is an "interesting observation," says Jennifer Y. King, a biogeochemist at the University of Minnesota in St. Paul. Because some types of soil microbes consume methane, they may prevent plant-produced methane from reaching the atmosphere. Field tests will be needed to assess the plant's influence, she notes.

单选题The polar regions are generally covered with ice and snow. A. areas B. rocks C. mountains D. seas

单选题Eight to ten million people around the world are now infected with the virus that causes AIDS, and the incidence of the infection is rising dramatically in some pans of the world, the World Health Organization reports. The estimate is (51) with an earlier projection by the organization that 15 million to 20 million people would be infected by HIV by the year 2005. The (52) reflect the growing (53) of the AIDS virus round the world. "It is clear that the problem of HIV infection around the globe is (54) rapidly, especially in (55) countries in Africa and Asia, "said Dr. Michael Merson, the director of the agency' s worldwide programs on AIDS. The new estimates are based on a recently (56) analysis of blood tests in which the AIDS virus was found in 1988 and 1989. The analysis showed that the (57) of HIV infection is slowing in industrialized countries. But in sub - Saharan African, cases of HIV infection have increased (58) about 5 million from 2.5 million in 1987. That year, most infected people were found in big cities; now the virus is spreading to (59) areas. The agency calculated that about one (60) 40 adult men and women is infected in that region. (61) from Southern Asia, including Thailand and India, showed marked increase in HIV infection among female prostitutes (妓女) and people who inject drugs into themselves. The (62) number of HIV infection in Asia has risen from next to nothing two years ago to at least 500,000, the agency reported. The agency also (63) a rising incidence of HIV infection, AIDS cases and (64) among women and children in the 2000s, with three million of them (65) to die in the next decade.

单选题 Regeneration of Limbs Most people would agree that it would be wonderful if humans could regenerate limbs. These who have lost their arms or legs would be complete again. The day is still far off when this might happen. But in the last 10 years, doctors have reported regeneration in smaller parts of the body, most often fingers. Regeneration is not a newly-discovered process. For centuries, scientists have seen it work in some kinds of animals. Break off a lizard's (蜥蜴的) tail, for example, and it will grow a new tail. Scientists now are looking for a way to turn on this exciting ability in more highly-developed animals, including humans. Their experiments show that nerves, cell chemistry and the natural electric currents in the body all seem to have a part in this process. The body of every animal contains general purpose cells that change into whatever kind of cells the body needs. Animals such as the lizard or salamander (蝾螈) use these cells to regenerate a new tail or leg when the old one is broken off. These cells collect around the wound. They form a mass called a blastama (胚基). The cells of the blastema begin to change. Some become bone cells, some muscle cells, some skin cells. Slowly, a new part regrows from the body outward. When completed, the new part is just like the old one. Mote than 200 years ago, Italian scientist Luigi Spallanzani showed that younger animals have a greater ability to regenerate lost parts than older animals. So do animals lower on the ladder of evolutionary development. The major difference seems to be that less-developed animals have more nerves in their tails and legs than humans do in their arms and legs. Another helpful piece of information was discovered in the late 1600s. Scientists found that when a creature is injured, an electrical current flows around the wound. The strength of the current depends on how severe the wound is and on how much nerve tissue is present. In 1945, American scientist Meryl Rose tested another idea about regeneration. He thought a new limb might grow only from an open wound. Doctor Rose cut off the front legs of some frogs, below the knee. He kept the wounds wet with a strong salty liquid. This prevented skin from growing over the wounds. The results were surprising. Frogs do not regenerate new legs naturally. But these frogs began to grow new limbs. About half of each cut-off leg grew back again. New bones and muscles developed. This research has led doctors to new ways of treating cut-off fingers. Doctors have observed, for example, that many children and some adults will regrow the top of a finger if the wound is left open.

单选题Do you follow what I am saying?

单选题She was grateful to him for being so good to her.

单选题The food is {{U}}insufficient{{/U}} for three people．

单选题Preventing Child Maltreatment Child maltreatment is a global problem with serious life-long consequences. There are no reliable global estimates or the prevalence of child maltreatment. Data for many countries, especially low-and middle-income countries, are lacking. Child maltreatment is complex and difficult to study. Current estimates vary widely depending on the country and the method of research used. Nonetheless, international studies reveal that approximately 20% of women and 5%-10% of men report being Sexually abused as children, while 25%-50% of all children report being physically abused. Additionally, many children are subject to emotional abuse (sometimes referred to as psychological abuse). Every year, there are an estimated 31,000 homicide deaths in children under 15. This number underestimates the true extent of the problem, as a significant proportion of deaths due to child maltreatment are incorrectly attributed to falls, burns and drowning. Child maltreatment causes suffering to children and families and can have long-term consequences. Maltreatment causes stress that is associated with disruption in early brain development. Extreme stress can impair the development of the nervous and immune systems. Consequently, as adults, maltreated children are at increased risk for behavioural, physical and mental health problems. Via the behavioural and mental health consequences, maltreatment can contribute to heart disease, cancer, suicide and sexually transmitted infections. Beyond the health consequences of child maltreatment, there is an economic impact, including costs of hospitalization, mental health treatment, child welfare, and longer-term health costs. It is important to emphasize that children are the victims and are never to blame for maltreatment. A number of characteristics of an individual child may increase the likelihood of being maltreated, such as being either under four years old or an adolescent, being unwanted, or failing to fulfil the expectations of parents and having special needs, crying persistently or having abnormal physical features.

单选题The department chairman refused to authorize the requisition.

单选题He is renowned for his skill.

单选题Warm People Likely to Keep Cold at Bay Staying positive through the cold season could be your best defense against getting ill, new study findings suggest. In an experiment that exposed healthy volunteers to a cold or flu virus, researchers found that people with a generally sunny disposition were less likely to fall ill. The findings, published in the journal Psychosomatic Medicine, build on evidence that a "positive emotional style" can help ward off the common cold and other illnesses. Researchers believe the reasons may be both objective as in happiness boosting immune function and subjective as in happy people being less troubled by a scratchy throat or runny nose. "People with a positive emotional style may have different immune responses to the virus," explained lead study author Dr Sheldon Cohen of Carnegie Mellon University in Pittsburgh. "And when they do get a cold, they may interpret their illness as being less severe. " Cohen and his colleagues had found in a previous study that happier people seemed less susceptible to catching a cold, but some questions remained as to whether the emotional trait itself had the effect. For the new study, the researchers had 193 healthy adults complete standard measures of personality traits, self-perceived health and emotional "style". Those who tended to be happy, energetic and easy-going were judged as having a positive emotional style, while those who were often unhappy, tense and hostile had a negative style. The researchers gave them nasal drops containing either a cold virus or a particular flu virus. Over the next six days, the volunteers reported on any aches, pains, sneezing or congestion they had, while the researchers collected objective data, like daily mucus production. Cohen and his colleagues found that based on objective measures of nasal woes, happy people were less likely to develop a cold.

单选题Eating Potatoes Gives Your Immune System a Boost Eating potatoes is not only good for bowel health, but also for the whole immune system, especially when they come in the form of a potato salad or eaten cold. In a study on an animal model, researchers in Spain found that pigs fed large quantities of raw potato starch (RPS) not only had a healthier bowel, but also decreased levels of white blood cells, such as leucocytes and lymphocytes in their blood. White blood cells are produced as a result of inflammation or disease, generally when the body is challenged. The general down-regulation of leucocytes observed by the Spanish researchers suggests an overall beneficial effect, a generally more healthy body. The reduction in leucocyte levels was about 15 percent. Lower lymphocyte levels are also indicative of reduced levels of inflammation, but the observed reduction in both lymphocyte density and lymphocyte apoptosis is surprising. In what was the longest study of its kind, pigs were fed RPS over 14 weeks to find out the effect of starch on bowel health. "The use of raw potato starch in this experiment is designed to simulate the effects of a diet high in resistant starch, " said study leader Jose Francisco Perez at the Universitat Autonoma de Barcelona, Spain. Humans do not eat raw potatoes, but they do eat a lot of foods that contain resistant starch, such as cold boiled potatoes, legumes, grains, green bananas, pasta and cereals. About 10 percent of the starch eaten by human is resistant starch — starch that is not digested in the small intestine and so is shunted into the large intestine where it ferments. Starch consumption is thought to reduce the risk of large bowel cancer and may also have an effect on irritable bowel syndrome (IBS). Immunology expert Lena Ohman's team previously found that the overall lymphocyte levels do not vary for IBS patients, but that lymphocytes are transferred from the peripheral blood to the gut, which support the hypothesis of IBS being at least partially an inflammatory disorder. She says the decrease in lymphocytes observed by the Spanish is therefore interesting, and a diet of resistant starch may be worth trying in IBS patients. Ohman is currently at the Department of Internal Medicine, Goteborg University, Sweden. The study is published in the journal Chemistry and Industry, the magazine of the SCI.

单选题The sea was calm and {{U}}still{{/U}}. A. quite B. quiet C. yet D. rough

单选题We all think that Mary"s husband is a very dull person.