单选题About eight million school-age children are home alone after school. These are the hours when the number of violent crimes peaks and when youths are most likely to experiment with alcohol, tobacco, and drugs. Many older children take care of themselves after school for an hour or two until a parent comes home, and research suggests that some of these children are more at risk of poor grades and risky behaviors. Studies have been done to find out what helps to reduce these kinds of risky behaviors among youths. One study of Chicago neighborhoods showed that after-school programs resulted in less violence even in poor neighborhoods. After-school programs can help to reduce crime and violence because they offer activities to children and youths during their out-of-school time. In addition to helping youths make use of after school hours, after-school programs provide teens with opportunities to develop caring relationships with adults. Studies have found that high-quality relationships with parents and other adults, as well as good use of time, are very important for healthy development in youth. After-school programs can also be used for teens who hang out at friends' houses and play basketball when a parent or other responsible adult is at home. The programs can also be helpful for formal after-school activities, including "drop-in" programs that are provided by organizations. Despite the benefits of after-school programs, there are many reasons why some parents do not use them. Programs may be too expensive, of poor quality, or hard to join. Some other children and young teens may refuse to attend programs that seem like they are just child care. Parents may feel uncertain about how much freedom is proper for children and youths who are beyond the traditional child care years. However, research supports the effectiveness of these programs in protecting middle school and high school youths from risk and harm.

单选题I understand that George can play piano {{U}}by ear{{/U}}; is that true?

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}} {{B}}Population Densities{{/B}} The average population density (密度) of the World is47 persons per square mile. Continental densities range from no permanent inhabitants in Antarctica to 211 per square mile in Europe. In the western hemisphere, population densities range from about 4 per square mile in Canada to 675 per square mile in Puerto Rico. In Europe the range is from 4 per square mile in Iceland to 831 per square mile in the Netherlands. Within countries there are wide variations of population densities. For example, in Egypt, the average is 55 persons per square mile, but 1,300 person inhabit each square mile in settled portions where the land is arable (适合耕种的). High population densities generally occur in regions of developed industrialization, such as the Netherlands, Belgium, and Great Britain, or where lands are intensively used for agriculture, as in Puerto Rico and Java. Low average population densities are characteristic of most Underdeveloped countries. Low density of population is generally associated 'with a relatively low percentage of cultivated land. This generally results from poor quality lands. It may also be due to natural obstacles to cultivation, such as deserts, mountains, or malaria-infested (疟疾横行) jungles; to land uses other than cultivation, as pasture and forested land; to primitive methods that limit cultivation; to social obstacles More economically advanced countries of low population density have, as a rule, large proportions of their populations living :in urban areas. Their rural population densities are usually very low. Poorly developed countries of correspondingly low population density, on the other hand, often have a concentration of rural population living on arable land, which is as great as the rural concentration found in the most densely populated industrial countries.

单选题Everybody was Uglad/U to see Mary back.

单选题He demolished my arguments in minutes.

单选题He was {{U}}elevated{{/U}} to the post of prime minister.

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。 {{B}}Survey Finds Many Women Misinformed about Cancer{{/B}} Sixty-three percent of American women think that if there's no family history of cancer, you're not likely to develop the disease, a new survey found. In fact, most people who develop cancer have no family history of cancer, according to the American College of Obstetricians and Gynecologists (ACOG) (美国妇产科医师学会), Which sponsored the survey. "Too many women are dying from cancer," Dr. Douglas W. Laube, ACOG's immediate past president, said during a Friday teleconference. "An estimated 200,070 women will die in the U. S. this year, and over 600,078 women will be diagnosed with cancer. The results of this survey found a worrisome (令人担扰的) gap in women's knowledge about cancer." Based on the findings, ACOG is increasing its efforts to educate women about cancer and the need for regular screening tests. Although the survey found many misconceptions (错误观念) about cancer, 76 percent of women surveyed did say they feel knowledgeable about how they can reduce their risk of the disease. However, only 52 percent said they were doing enough to reduce that risk. And 10 percent said they hadn't done anything in the past year to lower their risk. Seventeen percent said they wouldn't change their lifestyles, even if changes would lower their cancer risk. Many women said they were afraid to undergo screening out of fear of finding cancer. Twenty percent said they didn't want to know if they had cancer. In response to these findings, ACOG will launch on Oct. 29 a new website - Protect & Detect: What Women Should Know about Cancer. The guide is designed to help women to take charge of their health and improve their understanding of their risk of cancer - and the lifestyle steps they can take to cut that risk.

单选题 The Body Thieves In the early nineteenth century in Britain, many improvements were being made in the world of medicine. Doctors and Surgeons were becoming more knowledgeable about the human body. Illnesses that had been fatal a few years before were now curable. However, Surgeons had one problem. They needed dead bodies to cut up, or dissect (解剖). This was the only way that they could learn about the flesh and bones inside the body, and the only way to teach new surgeons to carry out operations. The job of finding these dead bodies was carried out by an unpleasant group of people called "body snatchers". They went into graveyards (墓地) at night and, using wooden shovels to make less noise, dug up any recently buried bodies. Then they took the bodies to the medical schools and sold them. A body could be sold for between ￡5 and 10, which was a lot of money at that time. The doctors who paid the body snatchers had all agreement with them—they never asked any questions. They did not desire to know where the bodies came from, as long as they kept arriving. The most famous of these body snatchers were two men from Edinburgh called William Burke and William Hare. Burke and Hare were different because they did not just dig up bodies from graveyards. They got greedy and thought of all easier way to find bodies. Instead of digging them up, they killed the poorer guests in Hare's small hotel. Dr. Knox, the respected surgeon they worked for, never asked why all the bodies they brought him had been strangled (勒死). For many years Burke and Hare were not caught because, unsurprisingly, the bodies of their victims were never found by the police. They were eventually arrested and put on trial in 1829. The judge showed mercy to Hare and he was released but Burke Was found guilty and his punishment was to be hanged. Appropriately, his body Was given to the medical school and he ended up on the dissecting table, just like his victims. In one small way, justice was done. Now, over 150 years later, surgeons do not need the help of criminals to learn their skills. However, the science of surgery could not have developed without their rather gruesome (令人毛骨悚然的) help.

单选题 Using HIV Virus to Cure Cancer Scientists are planning to use human immunodeficiency (免疫缺陷) virus (HIV), one of mankind's most feared viruses, as a carrier of genes which can fight cancer and a range of diseases that cannot be cured. The experts say HIV has an almost perfect ability to avoid the body's immune (免疫的) defenses, making it ideal for carrying replacement genes into patients' bodies, according to the Observer. A team at the California-based Salk Institute, one of the world's leading research centers on biological sciences, has created a special new breed of HIV and has started negotiations with the US Food and Drug Administration (FDA) to begin clinical gene therapy (治疗) trials this year. The first trials are expected to involve patients suffering from cancers that cannot be cured by surgery although project leader Professor Inder Verma said the HIV technique would have "far wider applications". The plan remains very likely to cause controversy since it involves making use of a virus which has caused more than 22 million deaths around the world in the past two decades. Verma said that the idea of using HIV for a beneficial purpose was "shocking" but the fierce nature of HIV had disappeared by having all six of the potentially deadly genes removed. Illnesses such as various cancers are caused when a gene in a patient's body fails to work properly. In the past two years, breakthroughs in genetics (遗传学) have led gene therapy scientists to try and replace the genes that do not function normally. Unfortunately, the body's immune defenses have been known to attack the modified genes and make them lose their effects before they can start their task and progress in the field has been held up by the lack of a suitable carrier. The HIV virus has the ability to escape from, and then destroy, the immune defense ceils designed to protect our bodies and this makes it attractive to scientists as a way of secretly conveying replacement genes into patients' bodies.

单选题The polar regions are generally covered with ice and snow.

单选题First editions of certain popular books cannot be obtained {{U}}for love or money{{/U}}. A.at any place B.at any price C.in any language D.in any country

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。 Among all cancers, lung cancer is the biggest killer: more than 100,000 Americans die of the disease each year. Giving up smoking is one way to reduce the risk, but another answer may lie in the kitchen, according to a report in British medical journal The Lancet. Since 1957, a team of researchers has monitored the dietary habits and medical histories of 2,000 middle-aged men employed by the Western Electric Co. in Chicago. Led by Dr. Pritichard Shekelle of Chicago's Rush--Presbyterian--St. Luke's medical Centre, the team recently began to sort out the links between the subjects' dietary patterns and cancer. Other animal and human studies has suggested that vitamin A might offer some protection against lung cancer, but did not distinguish vitamin A made in the body from that in carotene (胡萝卜素), which is abundant in a variety of vegetables and fruits, including carrots, spinach, broccoli, squash, tomatoes and apples. The Western Electric study showed little correlation (相互关系)between the incidence of lung cancer and the consumption of foods containing performed vitamin A. But the data on carotene intake (摄入)revealed a significant relationship. Among the 488 men who had the lowest carotene consumption, there were 14 cases of lung cancer; in a group of the same size that ate the most carotene, only two eases developed. The apparent protective effect of carotene held up even for long-time smokers. Further studies will be necessary before the link between lung cancer and carotene can be firmly established. Meanwhile, researchers warn against taking large amounts of vitamin-A supplements, which can be extremely poisonous in high doses. Instead, they advise a well-balanced diet that includes foods rich in carotene.

单选题Norwich, the capital of the part of Britain known as East Anglia, has been in existence for more than two thousand years. It began as a small village beside the River Wensum. At the time of the Norman invasion in 1066 it had grown to become one of the largest towns in England. In 1066, Norwich was still one of the smallest town in England.A. RightB. WrongC. Not mentioned

单选题If the right first more on the puzzle above has you stumped, look in the back of this magazine under Creative Problem Solving.A. boredB. angriedC. sadD. confused

单选题He isdetermined to consolidate his power.

单选题Some other illnesses may exhibit symptoms similar to those of flu and anthrax.

单选题{{B}}第二篇{{/B}} {{B}}Medical Journals{{/B}} Medical journals are publications that report medical information to physicians and other health professionals. In the past, these journals were available only in print. With the development of electronic publishing, many medical journals now have Web sites on the Internet, and some journals publish only online. A few medical journals, like the Journal of the American Medical Association, are considered general medical journals because they cover many fields of medicine. Most medical journals are specialty journals that focus on a particular area of medicine. Medical journals publish many types of articles. Research articles report the results of research studies on a range of topics varying from the basic mechanisms of diseases to clinical trials that compare outcomes of different treatments. Review articles summarize and analyze the information available on a specific topic based on a careful search of the medical literature. Because the results of individual research studies can be affected by many factors, combining results from different studies on the same topic can be helpful in reaching conclusions about the scientific evidence for preventing, diagnosing or treating a particular disease. Case conferences and case reports may be published in medical journals to educate physicians about particular illnesses and how to treat them. Editorials in medical journals are short essays that express the views of the authors, often regarding a research or review article published in the same issue. Editorials provide perspective on how the current article fits with other information on the same topic. Letters to the editor provide a way for readers of the medical journal to express comments, questions or criticisms about articles published in that journal.

单选题The best olive oil is obtained from olives that are harvested just after they ripen.______

单选题I must apologize for my {{U}}outrageous{{/U}} behavior.

单选题Trees, shrubs, flowers, and grass give character and interest to the parks. A. vines B. vegetables C. bushes D. weeds