Older Volcanic Eruptions Volcanoes were more destructive in ancient history, not because they were bigger, but because the carbon dioxide they released wiped out life with greater ease. Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large numbers of animals, but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock. To his surprise, the older the massive volcanic eruptions were, the more damage they seemed to do. He calculated the “killing efficiency“ for these volcanoes by comparing the proportion of life they killed off with the volume of lava(熔岩)that they produced. He found that size for size, older eruptions were at least 10 times as effective at wiping out life as their more recent rivals. The Permian(二叠纪)extinction, for example, which happened 250 million years ago, is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe. Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide. The global warming that followed wiped out 80 percent of all marine genera(种类)at the time, and it took 5 million years for the planet to recover. Yet 60 million years ago, there was another huge amount of volcanic activity and global warming but no mass extinction. Some animals did disappear but things returned to normal within ten thousand of years. “The most recent ones hardly have an effect at all, “ Wignall says. He ignored the extinction which wiped out the dinosaurs 65 million years ago, because many scientists believe it was primarily caused by the impact of an asteroid(小行星). He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO2. Vincent Courtillot, director of the Paris Geophysical Institute in France, says that Wignall’ s idea is provocative. But he says it is incredibly hard to do these sorts of calculations. He points out that the killing power of volcanic eruptions depends on how long they lasted. And it is impossible to tell whether the huge blasts lasted for thousands or millions of years. He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced, and that lava volume may not necessarily correspond to carbon dioxide emissions.

The Fat Problem That Men Face It is a pleasure to see men of a certain age worrying about their weight. Listening to them is not such a pleasure. Because the men are new at the game, they don’ t hesitate to discuss the fat problem incessantly. However, women of the same age do not discuss the fat problem, especially not in mixed company. They prefer to face the problem with quiet dignity. Discussing the problem might only draw attention to some stray body part that may be successfully tucked away under an article of clothing. The age at which a man begins to explore the fat problem can vary. The actual problem can manifest itself in the early 30’ s, but broad-range discussion usually starts later. There are early nonverbal symptoms. I’ ve watched the rugged journalist who shares my apartment sneak by with a Diet Coke. His shirts are no longer neatly tucked in to display a trim waist. Recently he has begun to verbalize his anxiety. He tells me, with a sheepish grin, that he is taking his suits to Chinatown to have them “tailored“. Still older men have lost their dignity and rattle on unabashedly. Often wives and children play important roles in their fat-inspection rituals. Take my oldest brother, a former college football player, as an example. His daughter says that several times a day he will stand at attention and call out, “ Fat, medium or thin?“ She knows the correct answer;medium. Thin would be an obvious stretch, and fat may not get her that new video. According to his wife, he stands in front of the mirror in the morning(before the day’ s meals take their toll), puts his hands behind his head and lurches into a side bend, then clutches the roll that has developed and says, “ Am 1 getting fatter?“ His wife is expected to answer, “You look like you may have lost a few pounds. “ And then there are the ex-husbands a pitiful group. They are extremely vocal. When I go to the movies with one, he confides that he is suffering from great hunger because he is dieting. He hasn’ t eaten since the pancakes and sausages he wolfed down that morning. He pauses in his monologue while he buys his popcorn. After the movie, we sprint to a restaurant, where he again pauses to devour a basket of bread. Before he orders his chaste salad and soup, he grows plaintive. Do I think he’ s fat?

Older Volcanic Eruptions Volcanoes were more destructive in ancient history, not because they were bigger, but because the carbon dioxide they released wiped out life with greater ease. Paul Wignall from the University of Leeds was investigating the link between volcanic eruptions and mass extinctions. Not all volcanic eruptions killed off large numbers of animals, but all the mass extinctions over the past 300 million years coincided with huge formations of volcanic rock. To his surprise, the older the massive volcanic eruptions were, the more damage they seemed to do. He calculated the “killing efficiency“ for these volcanoes by comparing the proportion of life they killed off with the volume of lava(熔岩)that they produced. He found that size for size, older eruptions were at least 10 times as effective at wiping out life as their more recent rivals. The Permian(二叠纪)extinction, for example, which happened 250 million years ago, is marked by floods of volcanic rock in Siberia that cover an area roughly the size of western Europe. Those volcanoes are thought to have pumped out about 10 gigatonnes of carbon as carbon dioxide. The global warming that followed wiped out 80 percent of all marine genera(种类)at the time, and it took 5 million years for the planet to recover. Yet 60 million years ago, there was another huge amount of volcanic activity and global warming but no mass extinction. Some animals did disappear but things returned to normal within ten thousand of years. “The most recent ones hardly have an effect at all, “ Wignall says. He ignored the extinction which wiped out the dinosaurs 65 million years ago, because many scientists believe it was primarily caused by the impact of an asteroid(小行星). He thinks that older volcanoes had more killing power because more recent life forms were better adapted to dealing with increased levels of CO₂. Vincent Courtillot, director of the Paris Geophysical Institute in France, says that Wignall’ s idea is provocative. But he says it is incredibly hard to do these sorts of calculations. He points out that the killing power of volcanic eruptions depends on how long they lasted. And it is impossible to tell whether the huge blasts lasted for thousands or millions of years. He also adds that it is difficult to estimate how much lava prehistoric volcanoes produced, and that lava volume may not necessarily correspond to carbon dioxide emissions.

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How Human’ s Personalities and Behaviors Are Formed 1 People have wondered for a long time how their personalities and behaviors are formed. It is not easy to explain why one person is intelligent and another is not, or why one is cooperative and another is competitive. 2 Social scientists are, of course, extremely interested in these types of questions. They want to explain why we possess certain characteristics and exhibit certain behaviors. There are no clear answers yet, but two distinct schools of thought on the matter have developed. As one might expect, the two approaches are very different from each other. The controversy is often conveniently referred to as “nature vs. nurture“. 3 Those who support the “ nature“ side of the conflict believe that our personalities and behavior patterns are largely determined by biological factors. That our environment has little, if anything, to do with our abilities, characteristics and behaviors is central to this theory. Taken to an extreme, this theory maintains that our behavior is pre-determined to such a great degree that we are almost completely governed by our instincts. 4 Those who support the “nurture“ theory, that is, they advocate education, are often called behaviorists. They claim that our environment is more important than our biologically based instincts in determining how we will act. A behaviorist, B. F. Skinner, sees humans as beings whose behavior is almost completely shaped by their surroundings. The behaviorists maintain that, like machines, humans respond to environmental stimuli as the basis of their behavior. 5 Let us examine the different explanations about one human characteristic , intelligence, offered by the two theories. Supporters of the “nature“ theory insist that we are born with a certain capacity for learning that is biologically determined. Needless to say, they don’ t believe that factors in the environment have much influence on what is basically a predetermined characteristic. On the other hand, behaviorists argue that our intelligence levels are the product of our experiences. Behaviorists suggest that the child who is raised in an environment where there are many stimuli which develop his or her capacity for appropriate responses will experience greater intellectual development. A. Environment Is Important B. Two Approaches Different From Each Other Are Formed C. People Want to Know How Their Personalities and Behaviors Are Formed D. Our Personalities and Behavior Patterns Are Largely Determined by Biological Factors E. We Want to Explain the Behaviors F. Two Similar Approaches Are Formed

US Blacks Hard-hit by Cancer Death rates for cancer are falling for all Americans, but black Americans are still more likely to die of cancer than whites, the American Cancer Society said Monday. In a special report on cancer and blacks, the organization said blacks are usually diagnosed with cancer later than whites, and they are more likely to die of the disease. This could be because of unequal access to medical care, because blacks are more likely to have other diseases like diabetes as well, and perhaps because of differences in the biology of the cancer itself, the report added. “ In general, African Americans have less likelihood of surviving five years after diagnosis than whites for all cancer sites and all stages of diagnosis, “ the report said. “In describing cancer statistics for African Americans, this report recognizes that socioeconomic disparities and unequal access to medical care may underlie many of the differences associated with race. “ The Cancer Society said blacks should be encouraged to get check-ups earlier, when cancer is more treatable, and it said more research was needed to see if biological differences play a role. “The new statistics emphasize the continuing importance of eliminating these social disparities through public policy and education efforts, “ the organization said in a statement. But it also noted a drop in cancer death rates. “Cancer death rates in both sexes for all sites combined have declined substantially among African Americans since 1992 , as have incidence rates, “ said the report. “Increased efforts to improve economic conditions in combination with education about the relationship of lifestyle choices to cancer could further reduce the burden of cancer among African Americans. “ Aboutr36 million Americans describe themselves as black, representing about 12 percent of the population.

The Sandwich Generation Today people often look forward to their middle age as a time when they will be able to take things easier. After their children are grown, they expect to enjoy the life they have worked hard to create.【B1】______ In middle age, many people discover that they have two ongoing responsibilities: one is to look after their aging parents, and the other is to help their young adult children deal with the pressures of life. Around the world, there are millions of people who are “ sandwiched“ in between the older and the younger generations. Sometimes there may be two or three generations living in the same household—a situation that is common in many Asian countries and in some parts of Europe. In other cases, a couple may be taking care of parents and children, but they do not live with them. There are two important reasons for the rise of the sandwich generation. First, people are living longer than they used to. In the early nineteenth century, the average life expectancy(预期寿命)for adults in the United States, for example, was about 40, whereas today people live to an average age of 75.【B2】______The second reason is that these days, young adults often live with their parents for a longer time than they did in the past. This is often for financial reasons. It’ s also more common for today’ s young adults to return home during or after college if they need financial or emotional support. 【B3】______They may have to cover expenses that their parents cannot. They may have to manage their parents’ financial and legal affairs. They may have to prepare for their parents’ future needs, such as special medical care or a move to a nursing home. This can be a traumatic(使人不快的)experience for everyone. Caring for adult children presents challenges as well, and caregivers have to resolve important questions: How can financial responsibilities be shared among members of the household? How can household chores be shared? What is the best way to ensure everyone’s privacy?【B4】______ The financial and emotional pressures on the sandwich generation can be overwhelming. However, this time in life also has its rewards.【B5】______It can also provide a valuable opportunity to spend more time with them. However, in order to survive this difficult period in their lives, the members of the sandAvich generation must remember that they also need to pay attention to their own needs and look after the quality of their own lives. They can’t be totally selfless. A. Successfully coping with these issues can avoid a lot of stress for the whole family. B. Therefore, children are taking care of their parents over a longer period of time. C. People who take care of elderly parents often face difficult issues. D. Young adults feel sandwiched between their financial responsibilities and their desire to enjoy life. E. However, the reality is often very different. F. It can be a time to rediscover the special qualities of one’ s parents or children.

Less Is More It sounds all wrong—drilling holes in a piece of wood to make it more resistant to knocks. But it works because the energy from the blow gets distributed throughout the wood rather than focusing on one weak spot. The discovery should lead to more effective and lighter packaging materials. Carpenters have known 【C1】______centuries that some woods are tougher than others. Hickory(山核桃木), for example, was turned into axe handles and cartwheel spokes(轮辐)because it can absorb shocks without breaking. White oak, for example, is much more easily damaged, 【C2】______it is almost as dense. Julian Vincent at Bathe University and his team were convinced that the wood’ s internal structure could explain the differences. Many trees have tubular(管状的)vessels that run【C3】______the trunk and carry water to the leaves. In oak they are large, and arranged in narrow bands, but in hickory they are smaller, and more evenly distributed. The researchers【C4】______this layout might distribute a blow’ s energy throughout the wood, soaking up a bigger hit. To test the idea, they drilled holes 0. 65 millimetres across into a block of spruce(云杉), a wood with【C5】______vessels, and found that【C6】______withstood a harder knock.【C7】______when there were more than about 30 holes per square centimetre did the wood’ s performance drop off. A uniform substance doesn’ t cope well with knocks because only a small proportion of the material is actually【C8】______. All the energy from the blow goes towards breaking the material in one or two places, but often the pieces left【C9】______are pristine(未经破坏的). But instead of the energy being concentrated in one place, the holes provide many weak spots that all absorb energy as they break, says Vincent. “ You are controlling the places【C10】______the wood breaks, and it can then absorb more【C11】______, more safely. “ The researchers believe the principle could be applied to any material—【C12】______example, to manufacture lighter and more protective packaging. It could【C13】______be used in car bumpers, crash barriers and armour for military vehicles, says Ulrike Wegst, a【C14】______at the Max Plank Institute for Mental Research in Stuttgart. But she emphasizes that you【C15】______to design the substance with the direction of force in mind. “The direction of loading is crucial, “ she says.

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Why did older volcanic eruptions do more damage than more recent ones?

How did Wignall calculate the killing power of those older volcanic eruptions?

When did dinosaurs become extinct?

What can be inferred from Paragraph 3 concerning dinosaurs?

What is the main thesis of the article?