Nuclear Power and Its Danger Nuclear power’s danger to health, safety, and even life itself can be summed up in one word;radiation. Nuclear radiation has a certain mystery about it, partly because it cannot be detected by human senses. It can’ t be seen or heard, or touched, or tasted, even though it may be all around us. There are other things like that. For example, radio waves are all around us but we can’t detect them, sense them, without a radio receiver. Similarly, we can’ t sense radioactivity without a radiation detector. But unlike common radio waves, nuclear radiation is not harmless to human beings and other living things. At very high levels, radiation can kill an animal or human being outright by killing masses of cells in vital organs. But even the lowest level of radiation can do serious damage. There is no level of radiation that is completely safe. If the radiation does not hit anything important, the damage may not be significant. This is the case when only a few cells are hit, and if they are killed outright. Your body will replace the dead cells with healthy ones. But if the few cells are only damaged, and if they reproduce themselves, you may be in trouble. They reproduce themselves in a deformed way. They can grow into cancer. Sometimes this does not show up for many years. This is another reason for some of the mystery about nuclear radiation. Serious damage can be done without the victim being aware at the time that damage has occurred. A person can be irradiated and feel fine, then die of cancer five, ten, or twenty years later as a result. Or a child can be born weak or liable to serious illness as result of radiation absorbed by its grandparents. Radiation can hurt us. We must know the truth.

Einstein’s Theory of Relativity was so profound that only a few scientists could understand it. deep superior wide narrow

Adult Education 1 Voluntary learning in organized courses by mature men and women is called adult education. Such education is offered to make people able to enlarge and interpret their experience as adults. Adults may want to study something which they missed in earlier schooling, get new skills or job training, find out new technological developments, seek better self-understanding, or develop new talents and skills. 2 This kind of education may be in the form of self-study with proper guidance through the use of libraries , correspondence courses, or broadcasting. It may also be acquired collectively in schools and colleges, study groups, workshops, clubs, and professional associations. 3 Modern adult education for large numbers of people started in the 18th and 19th centuries with the rise of the Industrial Revolution. Great economic and social changes were taking place;people were moving from rural areas to cities; new types of work were being created in an expanding factory system. These and other factors produced a need for further education and reeducation of adults. 4 The earliest programs of organized adult education arose in Great Britain in the 1790s, with the founding of an adult school in Nottingham and a mechanics institute in Glasgow. The earliest adult education institution in the United States was founded by Benjamin Franklin and some friends in Philadelphia in 1727. 5 People recognize that continued learning is necessary for most forms of employment today. For example, parts of the adult population in many countries find it necessary to take part in retraining programs at work or even to learn completely new jobs. Adult education programs are springing up constantly to meet these and other needs. A. Necessity for Developing Adult Education B. Early Days of Adult Education C. Ways of Receiving Adult Education D. Growth of Adult Education E. Institutions of Adult Education F. Definition of Adult Education

Pool Watch Swimmers can drown in busy swimming pools when lifeguards fail to notice that they are in trouble. The Royal Society for the Prevention of Accidents says that on average 15 people drown in British pools each year, but many more suffer major injury after getting into difficulties. Now a French company has developed an artificial intelligence system called Poseidon that sounds the alarm when it sees someone in danger of drowning. When a swimmer sinks towards the bottom of the pool, the new system sends an alarm signal to a pool-side monitoring station and a lifeguard’ s pager. In trials at a pool in Ancenis, near Nantes, it saved a life within just a few months, says Alistair McQuade, a spokesman for its maker, Poseidon Technologies. Poseidon keeps watch through a network of underwater and overhead video cameras. AI software analyses the images to work out swimmers’ trajectories. To do this reliably, it has to tell the difference between a swimmer and the shadow of someone being cast onto the bottom or side of the pool. “The underwater environment is a very dynamic one, with many shadows and reflections dancing around, “ says McQuade. The software does this by “projecting“ a shape in its field of view onto an image of the far wall of the pool. It does the same with an image from another camera viewing the shape from a different angle. If the two projections are in the same position, the shape is identified as a shadow and is ignored. But if they are different, the shape is a swimmer and so the system follows its trajectory. To pick out potential drowning victims, anyone in the water who starts to descend slowly is added to the software’s “pre-alert“ list, says McQuade. Swimmers who then stay immobile on the pool bottom for 5 seconds or more are considered in danger of drowning. Poseidon double-checks that the image really is of a swimmer, not a shadow, by seeing whether it obscures the pool’ s floor texture when viewed from overhead. If so, it alerts the lifeguard, showing the swimmer’s location on a poolside screen. The first full-scale Poseidon system will be officially opened next week at a pool in High Wycombe, Buckinghamshire. One man who is impressed with the idea is Travor Baylis, inventor of the clockwork radio. Baylis runs a company that installs swimming pools—and he was once an underwater escapologist with a circus. “I say full marks to them if this works and can save lives, “ he says. But he adds that any local authority spending ￡30, 000-plus on a Poseidon system ought to be investing similar amounts in teaching children to swim.

Medical Journals 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 are published 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 a 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.

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Accompanied by cheerful music, we began to dance. pleasant colorful fashionable different

Why is the Native Language Learnt So Well? How does it happen that children learn their mother tongue so well? When we compare them with adults learning a foreign language, we often find this interesting fact. A little child without knowledge or experience often succeeds in a complete mastery(精通)of the language. A grown-up person with fully developed mental powers, in most case, may end up with a faulty and inexact command(掌握). What accounts for this difference? Despite other explanations, the real answer in my opinion lies partly in the child himself, partly in the behavior of the people around him. In the first place, the time of learning the mother tongue is the most favorable of all, namely, the first years of life. A child hears it spoken from morning till night and, what is more important, always in its genuine form, with the right pronunciation, right intonation, right use of words and right structure. He drinks in(吸收)all the words and expressions, which come to him in a flash, ever-bubbling(冒泡的)spring. There is no resistance: there is perfect assimilation. Then the child has, as it were, private lessons all the year round, while an adult language-student has each week a limited number of hours, which he generally shares with others. The child has another advantage; he hears the language in all possible situations, always accompanied by the right kind of gestures and facial expressions. Here there is nothing unnatural, such as is often found in language lessons in schools, when one talks about ice and snow in June or scorching heat in January. And what a child hears is generally what immediately interests him. Again and again, when his attempts at speech are successful, his desires are understood and fulfilled. Finally, though a child’s “teachers“ may not have been trained in language teaching, their relations with him are always close and personal. They take great pains to make their lessons easy.

A. by social and economic changes B. guided self-study and correspondence courses C. by studying together with children D. what they did not manage to learn earlier E. dates back to the eighteenth century F. mass production

It is hard for the young people to imagine what severe conditions their parents once lived under. sincere hard strict tight

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Even in a highly modernized country, manual work is still needed. expressive physical exaggerated dubious

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These factors interact intimately and cannot be separated. tensely nearly carefully closely

She could not answer, it was an immense load off her heart. natural fatal tiny enormous

Radiation can cause serious consequences even at the lowest level______.

The underlined word “significant“ in Paragraph 3 most probably means______.

Radiation can hurt us in the way that it can______.

Which of the following can be best inferred from the passage?

According to the passage, the danger of nuclear power lies in______.