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. Which of the following can be best inferred from the passage
A. The importance of protection from radiation cannot be over-emphasized.
B. The mystery about radiation remains unsolved.
Cancer is mainly caused by radiation.
D. Radiation can hurt those who are not aware of its danger.
查看答案
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.
A. signs
B. designs
C. traits
D. points
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. Radiation can hurt us in the way that it can ______.
A. kill large numbers of cells in main organs so as to cause death immediately
B. damage ceils which may grow into cancer years later
C. affect the healthy growth of our offspring
D. all of the above
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. You interpret ______ by comparing it against the memories already stored in your brain.
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.
A. act
B. activity
C. action
D. acting