单选题Step Back in Time Do you know that we live a lot longer now than the people who were born before us? One hundred years ago the average woman lived to be 45. But now, she can live until at least 80. One of the main reasons for people living longer is that we know how to look after ourselves better. We know which foods are good for U. S. and what we have to eat to make sure our bodies get all the healthy things they need. We know why we sometimes get ill and what to do to get better again. And we know how important it is to do lots of exercise to keep our hearts beating healthily. But in order that we don"t slip back into bad habits, let"s have a look at what life was like 100 years ago. Families had between 15 and 20 children, although many babies didn"t live long. Children suffered from lots of diseases, especially rickets (佝偻病) and scurvy (坏血病), which are both caused by bad diets. This is because many families were very poor and not able to feed their children well. Really poor families who lived in crowded cities like London and Manchester often slept standing up, bending over a piece of string, because there was no room for them to lie down. People didn"t have fridges until the 1920s. They kept fresh food cold by storing it on windowsills(窗台板), blocks of ice, or even burying it in the garden. Some children had to start work at the age of seven or eight to earn money for their parents. If you had lived 100 years ago, you might well be selling matchsticks(火柴杆)(a job done by many children)or working with your dad by now.

单选题The study was the first to tell the difference between 7 and 8 hours of sleep a night.

单选题 World Heart Day Sunday was World Heart Day. The World Heart Federation and its member groups in more than one hundred countries organized the celebrations. The World Health Organization and other United Nations agencies provided support for the {{U}} {{U}} 1 {{/U}} {{/U}}. World Heart Day was first observed six years {{U}} {{U}} 2 {{/U}} {{/U}}. Organizers proposed the event as a way to help reduce the spread of heart disease. The World Heart Federation says heart {{U}} {{U}} 3 {{/U}} {{/U}}kills seven-teen million people each year. The group urges people to be active and have a good, healthy diet. It also warns {{U}} {{U}} 4 {{/U}} {{/U}}activities known to increase a person's risk of heart attack or stroke. Some of the warnings are directed at children. The World Heart Federation says about twenty-two million boys and girls under the age of five are obese-severely overweight. Children are normally energetic and active. {{U}} {{U}} 5 {{/U}} {{/U}}, two thirds of all children are not active enough. Such children greatly {{U}} {{U}} 6 {{/U}} {{/U}}their risk of becoming obese. They also increase their {{U}} {{U}} 7 {{/U}} {{/U}}of developing heart disease or other disorders. One message of World Heart Day is to eat right. Children {{U}} {{U}} 8 {{/U}} {{/U}}eat a healthy and balanced diet. Also, limit sugary drinks, sweets and eating between meals. The World Heart Federation urges parents to keep their children {{U}} {{U}} 9 {{/U}} {{/U}}. It says physical exercise helps to decrease the risk of obesity and {{U}} {{U}} 10 {{/U}} {{/U}}a child healthy. Obese children often become obese adults. {{U}} {{U}} 11 {{/U}} {{/U}}you believe your child is too heavy, talk with a health care provider. The World Heart Federation is also concerned about the effects of tobacco on young people. It says the younger someone begins to smoke, the {{U}} {{U}} 12 {{/U}} {{/U}}the chance of a health problem tied to smoking. Half of the young people who continue to smoke are {{U}} {{U}} 13 {{/U}} {{/U}}to die later in life from a smoking-related disease. The group says almost half of all children live with a smoker. It says children who live with a {{U}} {{U}} 14 {{/U}} {{/U}}can breathe an amount of tobacco equal to more than two thousand cigarettes. And that is by the time they are five years old. The World Heart Federation also says parents should warn children not to be {{U}} {{U}} 15 {{/U}} {{/U}}by tobacco companies. And it says parents who smoke should try to stop.

单选题It is easier to adapt to new situations if one has a flexible attitude.A. changeableB. fashionableC. moveableD. elastic

单选题A future government will be in the hands of {{U}}an extraordinary{{/U}} man, who was wrong punished twice, then clawed his way to the top.

单选题Gadfly was too much exhausted to wake easily when once asleep.A. worn outB.--drearyC. reluctantD. chary

单选题After a day's fierce fighting, the enemy finally had to {{U}}remove{{/U}} their troops from the occupied area.

单选题15 Million Americans Suffer from Social Anxiety Disorder Social anxiety disorder prevents some 15 million Americans from leading normal social and romantic lives, a new survey finds. The disorder leaves many isolated, ashamed and often misdiagnosed. Thirty-six percent of those with social anxiety disorder have symptoms for 10 years or more before seeking help, the Anxiety Disorders Association of America reports. "Social anxiety disorder is when somebody has an intense, persistent and irrational fear of social or performance situations," Jerilyn Ross, the association's president and CEO, said during a teleconference Wednesday. "The condition causes people to avoid common, everyday situations and even other people for fear of being judged or criticized or humiliated or embarrassing themselves," Ross said. Social anxiety disorder can interfere with daily routines and job performance, Ross noted. "It also makes it very difficult for people to develop friends and romantic partnerships," she said. People with this disorder recognize their fear is excessive and irrational, Ross noted. "But they feel powerless to do anything about it," she said. Social anxiety disorder can start in the early teens, Dr. Mark H. Pollack, director of the Center for Anxiety and Traumatic Stress Disorders and a professor of psychiatry at Harvard Medical School, said during the teleconference. "This is a disorder that starts affecting people early on," Pollack said. "The typical age of onset is early adolescence, age 12 or 13, and many individuals report a history of anxiety dating back to earlier childhood." The disorder also has physical symptoms, including heart palpitations, feelings that their throat will close up, sweating, blushing, faintness, trembling and stammering, Ross said. Among people with the disorder, 75 percent said the condition affected their ability to do normal activities. In addition, 69 percent said they didn't want people to think they were crazy, and 58 percent said they were embarrassed by their condition, Ross said. However, when the condition is diagnosed and treated, many reported improvement in their lives. In fact, 59 percent who were receiving treatment said treatment had a positive effect on their ability to have a romantic relationship. In addition, 39 percent who had received treatment said knowing that treatment can be successful aided their decision to get help, Ross noted.

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}} How to Determine a Topic for Research{{/B}} Because you are going to put a lot of your time and energy into your research project(项目),the topic is especially important. In many instances your instructor may give a specific(特殊的)topic. If this is done, you have little choice, but most instructors will permit or even welcome a slightly changed focus(中心)in a topic if it is supported by good thinking. In some of your classes, the instructor may present a suggested list of several topics from which you are to make a choice. If this is done, do not simply select the first idea that attracts your attention. It may be one with which you will soon become bored, or it may be one on which you would have difficulty finding all the necessary information. Looking at the topics, try to consider how you might go about developing each of them. When you find out what seems especially interesting and worthwhile(值得骄傲的),do a bit checking in the library to see if you can get the basic resources you will need. Choosing a good research topic does not necessarily mean finding something that has a lot written about it. Many times you will have to research around a topic in order to find out the most useful information. Exciting and original topics often come to mind by combining two completely different interests. Let us say that you are interested in child psychology(心理学的)and in sports. Perhaps you can combine these into a study of the effect that is watching(可得到的)on the subject, you can research the topic individually and, by putting your information together, then draw a conclusion.

单选题Engineers use the principles of aerodynamics in designing airplanes and other objects affected by aerodynamic forces.

单选题Have you talked to her lately ?

单选题A crowd gathered to see what had happened.

单选题It is {{U}}absurd{{/U}} to go out in such terrible weather.

单选题The used car {{U}}lot{{/U}} open until 9 o'clock.

单选题The Ice Age Twenty thousand years ago, the earth was held in control by relentlessly (不宽容地) probing fingers of ice that drew power from frigid strongholds in the north and crept southwestward to bury forests, fields, and mountains. Landscapes that were violated by the slowly moving glaciers(冰川)would carry the scars of this advance far into the future. Temperatures dropped deeply, and land surfaces in many parts of the world were depressed by the unrelenting weight of the thrusting ice. At the same time, so much was drawn from the oceans to form these huge glaciers that sea levels around the world fell by three hundred and fifty feet, and large areas of the continental shelf became dry land. This period of the Earth's history had come to be called the Ice Age. In all, about eleven million square miles of land were covered with ice. The Ice Age terminated about fourteen thousand years ago when the ice sheets began to retreat. It took about seven thousand years for the ice to retreat to its present level.

单选题How Deafness Makes It Easier to Hear Most people think of Beethoven"s hearing loss as an obstacle to composing music. However, he produced his most powerful works in the last decade of his life when he was completely deaf. This is one of the most glorious cases of the triumph of will over adversity, but his biographer, Maynard Solomon, takes a different view. Solomon argues that Beethoven"s deafness "heightened" his achievement as a composer. In his deaf world Beethoven could experiment, free from the sounds of the outside world, free to create new forms and harmonies. Hearing loss does not seem to affect the musical ability of musicians who become deaf. They continue to "hear" music with as much, or greater, accuracy than if they were actually hearing it being played. Michael Eagar, who died in 2003, became deaf at the age of 21. He described a phenomenon that happened within three months: "My former musical experiences began to play back to me. I couldn"t differentiate between what I heard and real hearing. After many years, it is still rewarding to listen to these playbacks, to "hear" music which is new to me and to find many quiet accompaniments for all of my moods." How is it that the world we see, touch, hear, and smell is both "out there" and at the same time within us? There is no better example of this connection between external stimulus and internal perception than the cochlear implant (人工耳蜗). No man-made device could replace the ability to hear. However, it might be possible to use the brain"s remarkable power to make sense of the electrical signals the implant produces. When Michael Eagar first "switched on" his cochlear implant, the sounds he heard were not at all clear. Gradually, with much hard work, he began to identify everyday sounds. "The insistent ringing of the telephone became clear almost at once." The primary purpose of the implant is to allow communication with others. When people spoke to Eagar, he heard their voices "coming through like a long-distance telephone call on a poor connection". But when it came to his beloved music, the implant was of no help. When he wanted to appreciate music, Eagar played the piano. He said, "I play the piano as I used to and hear it in my head at the same time. The movement of my fingers and the feel of the keys give added "clarity" to hearing in my head." Cochlear implants allow the deaf to hear again in a way that is not perfect, but which can change their lives. Still, when it comes to musical harmonies, hearing is irrelevant. Even the most amazing cochlear implants would have been useless to Beethoven as he composed his Ninth Symphony at the end of his life.

单选题 U.S. Blacks Hard-hit by Cancer Death rates for cancer are falling for all Americans, but black Americans are still more likely to die of cancer than whites, the American Cancer Society said Monday. In a special report on cancer and blacks, the organization said blacks are usually diagnosed with cancer later than whites, and they are more likely to die of the disease. This could be because of unequal (不平等的) access to medical care, because blacks are more likely to have other diseases as well, and perhaps because of differences in the biology (生物学) of the cancer itself, the report added. "In general, black Americans have less hope of surviving five years after diagnosis than whites for all cancer sites and all stages of diagnosis, "the report said. "In describing cancer statistics for black Americans, this report recognizes that many of the differences associated with race may be caused by unfair social and economic differences and unequal access to medical care." The cancer society said blacks should be encouraged to get check-ups (体格检查) earlier, when cancer is more treatable, and it said more research is needed to see if biological differences play a role. "The new statistics emphasize the continuing importance of wiping out these unfair social differences through public policy and education efforts," the organization said in a statement. But it also noted a drop in cancer death rates. "Cancer death rates in both sexes for all sites combined have dropped greatly among black Americans since 1992, as have incidence rates (发生率)," said the report.

单选题Exercise Weather or not exercise adds (1) the length of life, it is common experience that a certain (2) of regular exercise improves the health and contributes a feeling of well-being. Furthermore, exercise (3) involves play and recreation, and relieves nervous tension and mental fatigue in so doing, is not only pleasant but beneficial. How much and what kind of exercise one should (4) merits careful consideration. The growing child and the normal young man and young woman thrill with the exhilaration of strenuous sports. They fatigue to the (5) of exhaustion but recover promptly with a period of rest. But not so with (6) of middle age and beyond. For them moderation is (7) vital importance. Just how much exercise a person of a given age can safely take is a question (8) to answer. Individual variability is (9) great to permit of generalization. A game of tennis may be perfectly safe for one person of forty but folly for another. The safe limit for exercise (10) on the condition of the heart, the condition of the muscles, the type of exercise, and the regularity with which it is taken. Two general suggestions, however, will (11) as sound advice for anyone. The first is that the condition of the heart and general health should be (12) periodically by careful, thorough physical examinations. The (13) is that exercise should be kept below the point of physical exhaustion. What type of exercise one should (14) depends upon one's physical condition. Young people can safely enjoy vigorous competitive sports, but most older persons do better to limit themselves to less strenuous activities. Walking, swimming, skating are among the sports that one can enjoy and safely participate (15) throughout life. Regularity is important if one is to get the most enjoyment and benefit out of exercise.

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 U.S. 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 cells 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He was persuaded to Ugive up/U the idea.