题目内容
Nuclear Power and Its DangerNuclear 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 a result of radiation absorbed by its grandparents.Radiation can hurt us. We must know the truth. According to the passage, the danger of nuclear power lies in ______.
查看答案
搜索结果不匹配？点我反馈
更多问题
The Greatest Show on EarthThe Olympic Games are the greatest festival of sport in the world. Every four years, a hundred or more countries send their best sportsmen to compete for the highest honors in sport. As many as 6,000 people take part in over twenty sports. For the winners, there are gold medals and glory. But there is honor, too, for all who compete, win or lose. That is the spirit of the Olympics—to take part is what matters.The Olympic Games always start in a bright color and action. The teams of all the nations parade in the opening ceremony and march round the track. The custom is for the Greek team to march in first. For it was in Greece that the Olympics began. The team of the country where the Games are being held—the host country—marches in last.The runner with the Olympic torch then enters the stadium and lights the flame. A sportsman from the host country takes the Olympic oath on behalf of all the competitors. The judges and officials also take an oath. After the sportsmen march out of the stadium, the host country puts on a wonderful display.The competitions begin the next day. There are usually more than twenty sports in the Games. The rule is that there must be at least fifteen. The main events are in track and field, but it is a few days before these sports start. Each day the competitors take part in a different sport—riding, shooting, swimming, and cross-country running. Points are gained for each event. Medals are awarded for the individual winners and for national teams.More and more women are taking part in the Games. They first competed in 1900, in tennis and golf, which are no longer held in the Olympics. Women"s swimming events were introduced in 1912. But it was not until 1928 that there were any track and field events for women. Now, they compete in all but half a dozen of the sports. In horse riding, shooting, and boat racing, they may compete in the same events as the men. What are the most important events in the Olympic Games
Heat Is KillerExtremely hot weather is common in many parts of the world. Although hot weather just makes most people feel hot, it can 1 serious medical problems—even death. Floods, storms, volcano eruptions and other natural 2 kill thousands of people every year. So 3 extreme heat. Experts say heat may be nature"s deadliest killer. Recently, extreme heat was blamed 4 killing more than one hundred people in India. It is reported that the total heat of a hot day or several days can 5 health. Several hot days are considered a heat wave. Experts say heat waves often become dangerous when the nighttime temperature does not 6 much from the highest daytime temperature. This causes great stress on the human body.Doctors say people can do many things to 7 themselves from the dangers of extreme heat. Stay out of the sun, if possible. Drink lots of cool water. Wear light colored clothing made 8 natural materials; avoid wearing synthetic clothing. Make sure the clothing is 9 , permitting freedom of movement. And learn the danger 10 of the medical problems, such as headache and vomiting, that are linked to heat. Most people suffer only muscle pain as a(n) 11 of heat stress. The pain is a 12 that the body is becoming too hot. Doctors say those suffering headache or muscle pain should stop all activity, rest in a cool place and drink cool liquids. Do not return to physical 13 for a few hours because more serious conditions could develop.Doctors say some people face an 14 danger from heat stress. Such persons have a weak or damaged heart, high blood pressure, or other problems of the blood system.Hot weather also increases dangers for people who must take 15 for high blood pressure, poor blood flow, nervousness or depression.
How We Form First Impression1 We all have first impression of someone we just met. But why Why do we form an opinion about someone without really knowing anything about him or her—aside perhaps from a few remarks or readily observable traits.2 The answer is related to how your brain allows you to be aware of the world. Your brain is so sensitive in picking up facial traits, even very minor difference in how a person"s eyes, ears, nose, or mouth are placed in relation to each other makes you see him or her as different. In fact, your brain continuously processes incoming sensory information—the sights and sounds of your world. These incoming "signals" are compared against a host of "memories" stored in the brain areas called the cortex system to determine what these new signals "mean".3 If you see someone you know and like at school, your brain says "familiar and safe". If you see someone new, it says, "new-potentially threatening". Then your brain starts to match features of this stranger with other "known" memories. The height, weight, dress, ethnicity, gestures, and tone of voice are all matched up. The more unfamiliar the characteristics are, the more your brain may say, "This is new. I don"t like this person". Or else, "I"m intrigued". Or your brain may perceive a new face but familiar clothes, ethnicity, gestures—like your other friends; so your brain says, "I like this person". But these preliminary "impressions" can be dead wrong.4 When we stereotype people, we use a less mature form of thinking (not unlike the immature thinking of a very young child) that makes simplistic and categorical impressions of others. Rather than learn about the depth and breadth of people—their history, interest, values, strengths, and true character—we categorize them as jocks, geeks, or freaks.5 However, if we resist initial stereotypical impressions, we have a chance to be aware of what a person is truly like. If we spend time with a person, hear about his or her life, hopes, dreams, and become aware of the person"s character, we use a different, more mature style of thinking—and the most complex areas of our cortex, which allow us to be humane. Paragraph 3 ______
When Fear Takes Control of the MindA panic attack is a sudden feeling of terror. Usually it does not last long, but it may feel like forever. The cause can be something as normally uneventful as driving over a bridge or flying in an airplane. And it can happen even if the person has driven over many bridges or flown many times before. A fast heart beat. Sweaty hands. Difficulty in breathing. A light-headed feeling. At first a person may have no idea what is wrong. But these can all be signs of what is known as panic disorder. The first appearance usually is between the ages of 18 and 25. In some eases it develops after a tragedy, like the death of a loved one, or some other difficult situation.In the United States, the National Institute of Mental Health says more than two million people are affected in any one-year period. The American Psychological Association says panic disorder is twice more likely in women than men. And it can last anywhere from a few months to a lifetime.Panic attacks can be dangerous—for example, if a person is driving at the time. The Chesapeake Bay Bridge in the state of Maryland is so long and so high over the water, and it is famous for scaring motorists. There is even a driver assistance program to help people get across. Some people who suffer a panic attack develop a phobia, a deep fear of ever repeating the activity that brought on the attack.But experts say panic disorder can be treated. Doctors might suggest anti-anxiety or anti-depressant medicines. Talking to a counselor could help a person learn to deal with or avoid a panic attack. There are breathing methods, for example, that might help a person calm down. Panic disorder is included among what mental health professionals call anxiety disorders. A study published last week reported a link between anxiety disorders and several physical diseases. It says these include thyroid disease, lung and stomach problems, arthritis, migraine headaches and allergic conditions. Researchers at the University of Manitoba in Canada say that in most cases the physical condition follows the anxiety disorder. However, they say, exactly how the two are connected remains unknown.The report in theArchives of Internal Medicinecame from a German health study of more than 4,000 adults. The probability for American females to be affected by panic disorder is ______ that for American males.
微信支付 
支付宝支付