单选题. The predictability of our mortality rates is something that has long puzzled social scientists. After all, there is no natural reason why 2,500 people should accidentally shoot themselves each year or why 7,000 should drown or 55,000 die in their cars. No one establishes a quota for each type of death. It just happens that they follow a consistent pattern year after year. A few years ago a Canadian psychologist named Gerald Wilde became interested in this phenomenon. He noticed that mortality rates for violent and accidental deaths throughout the Western world have remained oddly static throughout the whole of the century, despite all the technological advances and increases in safety standards that have happened in that time. Wilde developed an intriguing theory called "risk homeostasis." According to this theory, people instinctively live with a certain level of risk. When something is made safer, people will get around the measure in some way to reassert the original level of danger. If, for instance, they are required to wear seat belts, they will feel safer and thus will drive a little faster and a little more recklessly, thereby statistically canceling out the benefits that the seat belt confers. Other studies have shown that where an intersection is made safer, the accident rate invariably falls there but rises to a compensating level elsewhere along the same stretch of road. It appears, then, that we have an innate need for danger. In all events, it is becoming clearer and clearer to scientists that the factors influencing our lifespan are far more subtle and complex than had been previously thought. It now appears that if you wish to live a long life, it isn't simply a matter of adhering to certain precautions.., eating the right foods, not smoking, driving with care. You must also have the right attitude. Scientists at the Duke University Medical Center made a 15-year study of 500 persons' personalities and found, somewhat to their surprise, that people with a suspicious or mistrustful nature die prematurely far more often than people with a sunny disposition. Looking on the bright side, it seems, can add years to your life span.11. What is it that social scientists have long felt puzzled about? ______
单选题1.
单选题. If you sit all day at an office and worry about its effect on your weight and health, take a few breaks. That's the advice from a new study that finds that people who sit for extended periods of time without taking short breaks are at higher risk for heart disease than those who take more frequent timeouts to stand up and walk around. The cardiovascular (心脏血管的) risk that stems from remaining sedentary for prolonged periods of time (at the office, for example) manifests itself in the form of larger waists, higher blood pressure, increased body inflammation and lower levels of "good" cholesterol (胆固醇), the authors noted. What's more, the negative impact of such lengthy bouts (一阵) of inactivity seems to apply even to those who routinely go to the gym. "These findings are not surprising," said Dr. Murray A. Mittleman, director of the cardiovascular epidemiology research unit at Beth Israel Deaconess Medical Center and an associate professor in the department of epidemiology at the Harvard School of Public Health in Boston. "In fact, the Surgeon General report recommends that individuals should accumulate activity incrementally throughout the day," noted Mittleman, who was not a member of the Australian research team. "And this is really consistent with that." The team, led by Genevieve N. Healy, of the Cancer Prevention Research Center in the School of Population Health at the University of Queensland in Herston, Australia, reported their findings in the Jan. 12 online edition of the European Heart Journal. "Even if you exercise for 30 to 60 minutes a day, what you do for the rest of the day may also be important for your cardiovascular health," Healy explained. "This research suggests that even small changes to a person's activity levels (as little as standing up regularly) might help to lower cardiovascular risk. These changes can be readily incorporated into the person's day-to-day life (including the work environment). Stand up, move more, more often, could be used as a slogan to help get this message across."1. What is the advice from a new study according to the passage? ______
单选题《复合题被拆开情况》 The world as we know it, some believe, needs fossil fuel to grow. "Global demand for energy is rising, driven by growing population with rising living standards," reads the Shell website. A
单选题《复合题被拆开情况》 Brain-training software may be a waste of time. People who played "mind-boosting" games made the same modest cognitive gains as those who spent a similar amount of time surfing the web. "It
单选题. Questions 12 to 15 are based on the conversation you have just heard.5.
单选题1.
单选题. Questions 22 to 25 are based on the passage you have just heard.7.
单选题《复合题被拆开情况》 The row over a Philadelphia school district accused of secretly spying on pupils through laptop cameras escalated today after it acknowledged capturing more than 56 000 images of its studen
单选题[此试题无题干]
单选题[此试题无题干]
单选题. Questions 12 to 15 are based on the conversation you have just heard.5.
单选题. Questions 3 and 4 are based on the news report you have just beard.3.
单选题. Questions 8 to 11 are based on the conversation you have just heard.1.
单选题. Questions 22 to 25 are based on the passage you have just heard.7.