单选题A study by scientists in Finland has found that mobile phone radiation can cause changes in human cells that might affect the brain, the leader of the research team said. But Darius Leszczynski, who headed the 2-year study and will present findings next week at a conference in Quebec (魁北克), said more research was needed to determine the seriousness of the changes and their impact on the brain or the body. The study at Finland's Radiation and Nuclear Safety Authority found that exposure to radiation from mobile phones can cause increased activity in hundreds of proteins in human cells grown in a laboratory, he said. "We know that there is some biological response. We can detect it with our very sensitive approaches, but we do not know whether it can have any physiological effects on the human brain or human body," Leszczynski said. Nonetheless, the study, the initial findings of which were published last month in the scientific journal Differentiation, raises new questions about whether mobile phone radiation can weaken the brain's protective shield against harmful substances. The Study focused on changes in cells that line blood vessels and on whether such changes could weaken the functioning of the blood-brain barrier, which prevents potentially harmful substances from entering the brain from the bloodstream, Leszczynski said. The study found that a protein called hsp27 linked to the functioning of the blood-brain barrier showed increased activity due to irradiation and pointed to a possibility that such activity could make the shield more permeable(能透过的), he said. "Increased protein activity might cause cells to shrink—not the blood vessels but the cells themselves—and then tiny gaps could appear between those cells through which some molecules could pass," he said. Leszczynski declined to speculate on what kind of health risks that could pose, but said a French study indicated that headache, fatigue and sleep disorders could result. "These are not life-threatening problems but can cause a lot of discomfort," he said, adding that a Swedish group had also suggested a possible link with Alzheimer's disease. "Where the truth is, I do not know," he said. Leszczynski said that he, his wife and children use mobile phones', and he said that he did not think his study suggested any need for new restrictions on mobile phone use.

单选题Stress makes a person want to stop whatever they are doing, try to relax, and become calm again. Too much stress results in physical, emotional, and mental health problems. There are numerous physical effects of stress. Stress can affect the heart. It can increase the pulse rate, make the heart miss beats, and can cause high blood pressure. Stress can affect the respiratory system. It can lead to asthma. It can cause a person to breathe too fast, resulting in a loss of important carbon dioxide. Stress can affect the stomach. It can cause stomach aches and problems digesting food. These are only a few examples of the wide range of illnesses and symptoms resulting from stress. Emotions are also easily affected by stress. People suffering from stress often feel anxious. They may have panic attacks. They may feel tired all the time. When people are under stress, they often overreact to little problems. For example, a normally gentle parent under a lot of stress at work may yell at a child for dropping a glass of juice. Stress can make people angry, moody, or nervous. Long-term stress can lead to a variety of serious mental illnesses. Depression, an extreme feeling of sadness and hopelessness, can be the result of continued and increasing stress. Alcoholism and other addictions often develop as a result of overuse of alcohol or drugs to try to relieve stress. Eating disorders, such as anorexia, are sometimes caused by stress and are often made worse by stress. If stress is allowed to continue, then one"s mental health is put at risk. It is obvious that stress is a serious problem. It attacks the body. So, reduce stress: stop the world and rest for a while.

单选题(Despite of) (many) attempts (to introduce) a universal language, notably Esperanto and Idiom Neutral(世界语和人造语言), the effort has met with very (little) success.

单选题He is used to flying by air and on no occasion ______ frightened. A) he has ever felt B) he ever feels C) ever does he feel D) has he ever felt

单选题A. How are you doing? B: ______

单选题For many people today, reading is no longer relaxation. To keep up their work they must read letters, reports, trade publications, interoffice communications, not to mention newspapers and magazines: a never-ending flood of words. In 21 a job or advancing in one, the ability to read and comprehend 22 can mean the difference between success and failure. Yet the unfortunate fact is that most of us are 23 readers. Most of us develop poor reading 24 at an early age, and never get over them. The main deficiency 25 in the actual stuff of language itself ——words. Taken individually, words have 26 meaning until they are strung together into phrases, sentences and paragraphs. 27 , however, the untrained reader does not read groups of words. He laboriously reads one word at a time, often regressing(退回) to 28 words or passages. Regression, the tendency to look back over 29 you have just read, is a common bad habit in reading. Another habit which 30 down the speed of reading is vocalization―sounding each word either orally or mentally as 31 reads. To overcome these bad habits, some reading clinics use a device called an 32 , which moves a bar (or curtain) down the page at a predetermined(预先确定的) speed. The bar is set at a slightly faster rate 33 the reader finds comfortable, in order to "stretch" him. The accelerator forces the reader to read fast, 34 word-by-word reading, regression and subvocalization(默读)practically impossible. At first 35 is sacrificed for speed. But when you learn to read ideas and concepts, you will not only read faster, 36 your comprehension will improve. Many people have found 37 reading skill drastically improved after some training. 38 Charlce Au, a business manager, for instance, his reading rate was a reasonably good 172 words a minute 39 the training, now it is an excellent 1,378 words a minute. He is delighted that how he can 40 a lot more reading material in a short period of time.

单选题Many people imagine that Alzheimer"s disease, the degenerative disorder that ultimately leaves sufferers with total memory loss, is an inevitable result of aging. This is not so. 【C1】______the risks of contracting the disease increase with age, there are many elderly people【C2】______memories are perfect. Most of us are so ill-【C3】______about all forms of memory loss that we label everything "Alzheimer"s". Alzheimer"s disease itself can【C4】______people as young as 30 and can progress either quickly or slowly. It can also【C5】______the blame for other non-degenerative conditions such as deep depression. 【C6】______, only an examination of the brain tissue during all autopsy can produce an accurate【C7】______of the disease. The causes of Alzheimer"s are unknown. They may be either【C8】______or environmental. A study in 1996 of 13, 000 people whose parents or siblings had the disease showed they had five times【C9】______chance of succumbing【C10】______the age of 80 than those with no family【C11】______of the problem. There are other factors, however. In a study of identical twins, it was found that only about half of the twin pairs developed Alzheimer"s and, when both twins【C12】______it, they did so as【C13】______as 15 years apart. The possibility【C14】______environment plays a part was【C15】______by another 1996 study, this time of two groups of elderly Japanese men. One group lived in Hawaii, the other in Japan. The Hawaiian group had a much higher【C16】______of the disease. Aluminum has been blamed for, the development of Alzheimer"s. This is because a high level of aluminum has been found in the brains of sufferers. The disease was first diagnosed at the beginning of the 20th century. It was at this time【C17】______aluminum was becoming widely available for use in cooking pots. Memory loss, difficulty in【C18】______familiar tasks, and problems with abstract thinking are all【C19】______of the onset of the disease. One unusual feature is its impact on language. It attacks nouns first, 【C20】______verbs. Grammar is one of the last things to go.

单选题The web sites can be used to______books that have long been out of print.

单选题Officials are supposed to ____ themselves to the welfare and health of the general public.

单选题The details of the geological history of the Rocky Mountains have been lost______hundreds of millions of years.

单选题If I correct someone, I will do it with as much good humor and self-restraint as if I were the one ______. A. correcting B. to correct C. to be corrected D. being corrected

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单选题With a candle in hand, he carefully ______ the narrow stairs to his bedroom. A. asserted B. ascertained C. assembled D. ascended

单选题{{B}}Passage 3{{/B}} There are many good reasons for great current attention to university-industry relations, but there are troublesome reasons as well. One is that universities are now unusually hungry. There is nothing wrong with hunger. But a hungry man may cut comers in his rush to nourishment, and he may be taken advantage of in negotiations. Fear of this is leading to the threat of protectionism, as exemplified by recent attempts to classify or otherwise control access to university research, including that joint with industry. In designing university-industry connections, protecting interests by high-level negotiations is wrong. Protectionism is dangerous and habit-forming. Circumstances exist where it is appropriate, but only for a short time. One of the few essentials of agreements is that any secrecy or interference with open publication or student interaction should be strictly temporary. The dominant problem of supporting enough basic research in universities will remain. This must continue to be a federal responsibility; no company or industry can harvest the results soon enough to justify any investment larger than keeping a window on basic research and conduit for the movement of bright young people into the company. Hard work in the universities will lead to important cooperative research agreements with industry, but unremitting effort will be required to maintain or enlarge the basic research on which all else rests. But there is far more at stake than support for universities. University-industry interaction should not be looked upon as support at all, but as an absolutely necessary part of the survival both of American institutions and of the American economy. As the economy stumbles, protectionism of all kinds becomes rampant, and everyone loses. From the university's standpoint, cooperative projects with industry affect graduate (and even undergraduate) work in healthy ways. To use Harvey Brooks's phrase, giving students "respect for applied problems" is an important part of their education. Wisdom begins when students (and even professors) realize that an invention is not a product and a product is not an industry. What is perhaps most at stake is attracting some of the ablest young people to those fields that can make a difference in the survival of our society. Particle physics ought to be done, just as art galleries ought to be maintained, and the richer the country is the more particle physics and art galleries it should support. But it would be a disaster if protectionism, of either the government or the industry variety, were to discourage some of the best young people from going into applied fields.

单选题Constance Hale says "email has been an incredible boon to communication". What does she mean by this?

单选题A. committee B. employee C. guarantee D. disagree