单选题The Barbie Dolls In the mid 1940's, the young ambitious Ruth and Elliot Handler, owned a company that made wooden pictures frames. It was in 1945 that Ruth and Elliot Handler joined with their close friend Harold Mattson to form a company that would be known for the most famous and successful doll ever created. This company would be named Mattel, MATT for Mattson, and EL for Elliot. In the mid 1950's, while visiting Switzerland, Ruth Handler purchased a German Lilli doll. Lilli was a shapely, pretty fashion doll first made in 1955. She was originally fashioned after a famous cartoon character in the West German Newsletter, Build. Lilli is the doll that would inspire Ruth Handler lo design the Barbie doll. With the help of her technicians and engineers at Mattel, Barbie was horn. Ruth then hired Charlotte Johnson, a fashion designer, to create Barbie's, wardrobe, h was in 1958 that the patent lot Barbie was obtained. This would be a fashion doll unlike any of her time. She would be long limbed, shapely, beautiful, and only 11.5 inches tall. Ruth and Elliot would name their new fashion doll after their own daughter, Barbie. In 1959, the Barbie doll would make her way to the New York Toy Show and receive a cool reception from the toy buyers. Barbie has undergone a lot of changes over the years and has managed to keep up with current trends in hairstyles, makeup and clothing. She is a reflection of the history of fashion since her introduction to the toy market. Barbie has a universal appeal and collectors both young and old enjoy time spent and memories made with their dolls.

单选题Domestic demand may thus decelerate to a more sustainable growth rate, and the unemployment rate may rise slightly.A. andB. in this wayC. laterD. this

单选题Active in Old Age Keeps People Mobile People over 70 who aren"t active are more likely to develop problems walking or climbing stairs within a few years, according to a new study. These findings suggest that it"s very important to stay 16 in old age, study author Dr. Marjolein Visser told Reuters Health. "Physical activity in old age is as important 17 taking your medications (药物 )," Visser noted. "You do not need to join an expensive, fancy sports club with hightech (高科技的) equipment. Your body will already 18 from regular walking." Visser, a Dutch (荷兰的) scholar, explained that 19 active helps prevent people from becoming breathless during simple activities, increase muscle mass and strength, and maintain the balance people need to walk up stairs, for instance. To investigate how important exercise is to older adults, Visser"s team interviewed 3,075 men and 20 between the ages of 70 and 79, all of whom said they had no problems walking one-quarter of a mile or climbing 21 . The investigators followed the subjects for 4.5 years, noting who developed problems 22 and climbing stairs. During the study, 34 percent of men and 47 23 of women said they began to struggle with walking and climbing stairs. People 24 were inactive were twice as likely to report these problems as people who said they got regular exercise. People who didn"t exercise but had active lifestyles appeared to be at a somewhat higher risk of developing 25 walking and climbing stairs, relative to people who exercised 26 . Still, leading an active lifestyle appeared to protect people 27 problems better than being generally inactive, the researchers report in the Journal of the American Geriatrics (老年医学) Society. Among people who were inactive, 28 who walked even a little bit such as brisk (轻快的) walking for a little over an hour per week—were at a lower 29 of mobility (可动性) problems. "If you do not like to exercise or you cannot exercise 30 of serious health problems or functional limitations, do try to be as active as possible," Visser advised.

单选题 阅读下面这篇短文，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。 {{B}}Cosmetic Surgery{{/B}} Surgery that can improve the way a person looks is becoming more and more popular in the United States. This kind of surgery is called cosmetic surgery, and both men and women are turning to this treatment as a way of keeping their appearance young as well as keeping competitive (有竞争力的) in their jobs. Men especially are beginning to turn to face-lifts (面部拉皮手术), liposuction (taking fat out of the body), and implants (putting artificial parts into their bodies) to help them look younger. As companies downsize (缩编) and move younger employees into higher positions, older employees in their late forties and early fifties feel the need to look and act younger in order to stay competitive. These operations are not without dangers, however. One young woman had an eye operation to get rid of the bags under her eyes. She described her experience as terrible. She said, "When he started cutting, I was fully awake. Even though he'd given me an injection near my eyes, I saw everything." She went on to explain, "1 knew I had to keep still because of what he was doing. He was scraping (刮) away fat underneath my eyes. It took about ten minutes. After he finished, I felt I couldn't walk. I was so faint." Her troubles did not end after the operation for two weeks. Her eyes were swollen (肿胀的) and almost completely closed, and even dark glasses could not hide the side effects of the operation. Liposuction, taking fat out of the body, is probably the most popular cosmetic operation in the United States. It seems simple enough. First, a small cut is made over the place where the patient wants the fat removed. Next, a small pipe is put into the cut. A machine like a vacuum cleaner is then used to suck the fat out of the body. However, as one doctor explained, some problems can happen after the operation. He warned, "Irregular lumps and loose skin can result from this operation. If it is not evenly done, liposuction can produce a very lumpy result." Patients often must have more liposuction to correct the problem.

单选题He asserted that nuclear power was a safe and non-polluting energy source.A. maintainedB. recommendedC. consideredD. acknowledged

单选题It is the lack of money that has held up the progress In using replacement genes to cure cancer.

单选题The sea turtle's natural habitat has been considerably reduced. A. suddenly B. greatly C. generally D. slightly

单选题We haven't yet been able to find a house that meets our requirements.A. accordsB. satisfiesC. suitsD. includes

单选题They are concerned for the fate of the forest and the Indians who {{U}}dwell{{/U}} in it.

单选题下面有3篇短文，每篇短文后有5道题。请根据短文内容，为每题确定1个最佳选项。 {{B}}第一篇{{/B}} Human Heart Can Make New Ceils Solving a longstanding (为时甚久的) mystery, scientists have found that the human heart continues to generate new cardiac (心脏的) cells throughout the life span, although the rate of new cell production slows with age. The finding, published in the April 3 issue of Science, could open a new path for the treatment of heart diseases such as heart failure and heart attack, experts say. "We find that the beating cells in the heart, cardiomyocytes (心肌细胞), are renewed," said lead researcher Dr. Jonas Frisen, a professor of stem cell research at the Karolinska Institute in Stockholm, Sweden. "It has previously not been known whether we were limited to the cardiomyocytes we are born with or if they could be renewed," he said. The process of renewing these cells changes over time, Frisen added. In a 20-year-old, about 1 percent of cardiomyocytes are exchanged each year, but the turnover (更替) rate decreases with age to only 0.45 percent by age 75. "If we can understand how the generation of new cardiomyocytes is regulated, it may be potentially possible to develop pharmaceuticals (药物) that promote this process to stimulate regeneration after, for example, a heart attack," Frisen said. That could lead to treatment that helps restore damaged hearts. "A lot of people suffer from chronic heart failure," noted co-author Dr. Ratan Bhardwaj, also from the Karolinska Institute. "Chronic heart failure arises from heart cells dying," he said. With this finding, scientists are "opening the door to potential therapies (疗法) to having ourselves heal ourselves," Bhardwaj said. "Maybe one could devise a pharmaceutical agent that would make heart cells make new and more cells to overcome the problem they are facing. " But barriers remain. According to Bhardwaj, scientists do not yet know how to increase heart cell production to a rate that would replace cells faster than they are dying off, especially in older patients with heart failure. In addition, the number of new cells the heart produces was estimated using healthy hearts -- whether the rate of cell turnover in diseased hearts is the same remains unknown.

单选题Over 25% of people are estimated to have difficulty with night vision due to ______

单选题The boy's death was {{U}}disastrous{{/U}} to him. The poor man never got over from it.

单选题Why did her friends and neighbours stop seeing her after a few months?

单选题We must {{U}}abide by{{/U}} the rules.

单选题 Throughout the world there is a shortage of human organs for transplants. In Britain, for example, 6000 people are waiting for organs ——5000 for kidneys, and the {{U}}(51) {{/U}} for hearts, lungs and livers. {{U}}(52) {{/U}}, only about 1750 kidney, 500 heart and lung, and 650 liver transplants are {{U}}(53) {{/U}} each year. And the waiting {{U}}(54) {{/U}} increases at five percent a year. In the United States only half of the 30000 in need of organs {{U}}(55) {{/U}} them. Hence the great interest in animal-to-human transplants, known as xenografts or xenotransplants (from the Greek work xenos, meaning strange of foreign) {{U}}(56) {{/U}} most scientists believe is the only long-term solution to the organ {{U}}(57) {{/U}}. There have been attempts at xenotransplants {{U}}(58) {{/U}} the beginning of this century but neither has been successful; the longest {{U}}(59) {{/U}} was a 20-day-old baby called Fae, who in 1984 was {{U}}(60) {{/U}} the heart of a baboon. The main {{U}}(61) {{/U}} with any organ transplant is that the immune system of the patient receiving the organ sees the transplant organ {{U}}(62) {{/U}} an invader. The immune system therefore launches a massive attack on the invader, activating enzymes knows as complement, which attack the {{U}}(63) {{/U}} body, eventually killing the patient as well. This rejection has been {{U}}(64) {{/U}} when transplanting human organs between humans by the close matching of tissue and the long-term use of drugs known as immuno-suppressants, first introduced just over ten years ago. With xenotranplants, however, rejection is even more {{U}}(65) {{/U}}; a normal pig's heart, for example, transfuses with human blood can be destroyed in 15 minutes.

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. At 30 degrees, 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He was acquitted on charges of assault with a deadly weapon.

单选题The government would not dare to impose taxes on such necessities as bread or milk.A. cutB. forceC. occurD. charge

单选题Sleep Lets Brain File Memories To sleep. Perchance to file? Findings published online this week by the Proceedings of the National Academy of Science further support the theory that brain organizes and stows memories formed during the day while the rest of the body is catching zzz"s. Gyorgy Buzsaki of Rutgers University and his colleagues analyzed the brain waves of sleeping rats and mice. Specifically, they examined the electrical activity emanating from the somatosensory neocortex (an area that processes sensory information) and the hippocampus, which is a center for learning and memory. The scientists found that oscillations in brain waves from the two regions appear to be intertwined. So-called sleep spindles (bursts of activity from the neocortex) were followed tens of milliseconds later by beats in the hippocampus known as ripples. The team posits that this interplay between the two brain regions is a key step in memory consolidation. A second study, also published online this week by the Proceedings of the National Academy of Sciences, links age-associated memory decline to high glucose level. Previous research had shown that individuals with diabetes suffer from increased memory problems. In the new work, Antonio Convit of New York University School of Medicine and his collaborators studied 30 people whose average age was 69 to investigate whether sugar levels, which tend to increase with age, affect memory in healthy people as well. The scientists administered recall tests, brain scans and glucose tolerance tests, which measure how quickly sugar is absorbed from the blood by the body"s issues. Subjects with the poorest memory recollection, the team discovered, also displayed the poorest glucose tolerance. In addition, their brain scans showed more hippocampus shrinkage than those of subjects better able to absorb blood sugar. "Our study suggests that this impairment may contribute to the memory deficits that occur as people age," Convit says. "And it raises the intriguing possibility that improving glucose tolerance could reverse some age-associated problems in cognition." Exercise and weights control can help keep glucose level in check, so there may be one more reason to go to the gym.

单选题A well-known physician agreed to perform the operation.A. A famousB. An expensiveC. An incompetentD. A talented