You'd better ______ from talking too much

When I try to understand ______ that prevents so many Americans from being happy as one might expect, it seems to me that there are two causes.

The American baby boom after the war made unconvincing U.S. advice to poor countries that they restrain their births. However, there has hardly been a year since 1957 in which birth rates have not fallen in the United States and other rich countries, and in 1976 the fall was especially sharp. Both East Germany and West Germany have fewer births than they have deaths, and the United States is only temporarily able to avoid this condition because the children of the baby boom are now an exceptionally large group of married couples. It is true that Americans do not typically plan their births to set an example for developing nations. We are more affected by women's liberation: once women see interesting and well-paid jobs are careers available, they are less willing to provide free labor for child raising. From costing nothing, children suddenly come to seem impossibly expensive. And to the high cost of children are added the uncertainties, introduced by divorce; couples are increasingly unwilling to subject children to the terrible experience of marital breakdown and themselves to the difficulty of raising a child alone. These circumstances—women working outside the home and the instability of marriage—tend to spread with industrial society and they will affect more and more countries in the near future. Along with them goes social mobility, ambition to rise in the urban world, a main factor in bringing down the births in Europe in the 19th century. Food shortage will happen again when the reserves resulting from the good harvests of 1998 and 1999 have been consumed. Urbanization is likely to continue, with the cities of the developing nations struggling under the weight of twice their present populations by the year 2010. The presently rich countries are approaching a stable population largely because of the changed place of women, and they incidentally are setting an example of restraint to the rest of the world. Industrial society will spread to the poor countries, and aspiration will exceed resources. All this will lead to a population in the new century that is smaller than was feared a few years ago. For those anxious to see world population brought under control, the news is encouraging. What influences the birth rate most in the United States is ______.

Every time a person eats something he makes a nutritional decision. He accepts or rejects the food available to him at home for meals or snacks. Or he selects food for himself at many places in the community, such as supermarkets, drive-ins, restaurants, and food counters in drugstores. These selections make a difference in how an individual looks, how he feels, and how well he can work and play. When a good assortment of food in appropriate amounts is selected and eaten, the consequences are more likely to be a desirable level of health and enough energy to allow one to be as active as one needs and wants to be. When choices are less than desirable, the consequences are likely to be poor health or limited energy or both. Studies of diets of individuals in the United States show that food selection is a highly individual matter, even among young children. Furthermore, far too many individuals of all ages are making poor choices day after day and are either now living with the consequences or will be in the future. Nutritionists and workers in allied professions have been concerned about helping people learn to select and enjoy a wide variety of food combinations that can add up to a good diet. Most people believe that they are well fed—that the choices they make are good ones. After all, they are not really sick, neither are they hungry. However, their nutrition is usually poor in one respect or another. Milk and milk products, such as cheeses, ice cream or milk, buttermilk, and yogurt, are often slighted. Then people may skip many fruits and vegetables, particularly those that are good sources of vitamins A and C. These include dark green leafy vegetables, deep yellow vegetables, and citrus fruits and vegetables, such as cabbage, tomatoes, and green peppers. Every American has the right to choose to be uniformed about nutrition as well as to be informed. If a person believes that she is well fed, attitudes, habits, and information cannot be forced upon her. There are life situations, however, that tend to cause all individuals to want to know how to make the best choices. For example, a young couple is starting a family and must prepare food for young children. Food preference in America is ______.

In general

She had a terrible accident

The Japanese take pride in doing a job and getting it done ______ much time is required.

He is quite worn out from years of hard work

After doing odd jobs for a week

Naturally

In the ______ of human life the honors and rewards fall to those who show their good qualities in action.

阅读理解 If you are reading this article, antibiotics have probably saved your life—and not once but several times. A rotten tooth, a knee operation, a brush with pneumonia; any number of minor infections that never turned nasty. You may not remember taking the pills, so unremarkable have these one-time wonder drugs become. Modern medicine relies on antibiotics—not just to cure diseases, but to augment the success of surgery, childbirth and cancer treatments. Yet now health authorities are warning, in uncharacteristically apocalyptic terms, that the era of antibiotics is about to end. In some ways, bacteria are continually evolving to resist the drugs. But in the past we've always developed new ones that killed them again. Not this time. Infections that once succumbed to everyday antibiotics now require last-resort drugs with unpleasant side effects. Others have become so difficult to treat that they kill some 25,000 Europeans yearly. And some bacteria now resist every known antibiotic. Regular readers will know why: New Scientist has reported warnings about this for years. We have misused antibiotics appallingly, handing them out to humans like medicinal candy and feeding them to livestock by the tonne, mostly not for health reasons but to make meat cheaper. Now antibiotic-resistant bacteria can be found all over the world—not just in medical facilities, but everywhere from muddy puddles in India to the snows of Antarctica(南极洲). How did we reach this point without viable successors to today's increasingly ineffectual drugs? The answer lies not in evolution but economics. Over the past 20 years, nearly every major pharmaceutical company has abandoned antibiotics. Companies must make money, and there isn't much in short-term drugs that should be used sparingly. So researchers have discovered promising candidates, but can't reach into the deep pockets needed to develop them. This can be fixed. As we report this week, regulatory agencies, worried medical bodies and Big Phar-ma are finally hatching ways to remedy this market failure. Delinking profits from the volume of drug sold (by adjusting patent rights, say, or offering prizes for innovation) has worked for other drugs, and should work for antibiotics—although there may be a worryingly long wait before they reach the market. One day, though, these will fall to resistance too. Ultimately, we need, evolution-proof cures for bacterial infection: treatments that stop bacteria from causing disease, but don't otherwise inconvenience the little blighters. When resisting drugs confers no selective advantage, drugs will stop breeding resistance. Researchers have a couple of candidates for such treatment. But they fear regulators will drag their feet over such radical approaches. That, too, can be fixed. We must not neglect development of the sustainable medicine we need, the way we have neglected simple antibiotic R D. If we do, one day another top doctor will be telling us that the drugs no longer work—and there really will be no help on the way.

阅读理解 The biggest thing in operating rooms these days is a million-dollar, multi-armed robot named da Vinci, used in nearly 400,000 surgeries nationwide last year—triple the number just four years earlier. But now the high-tech helper is under scrutiny over reports of problems, including several deaths that may be linked with it and the high cost of using the robotic system. There also have been a few disturbing, freak incidents: a robotic hand that wouldn't let go of tissue grasped during surgery and a robotic arm hitting a patient in the face as she lay on the operating table. Is it time to curb the robot enthusiasm? Some doctors say yes, concerned that the 'wow' factor and heavy marketing have boosted use. They argue that there is not enough robust research showing that robotic surgery is at least as good or better than conventional surgeries. Many U. S. hospitals promote robotic surgery in patient brochures, online and even on highway billboards. Their aim is partly to attract business that helps pay for the costly robot. The da Vinci is used for operations that include removing prostates, gallbladders and wombs, repairing heart valves, shrinking stomachs and transplanting organs. Its use has increased worldwide, but the system is most popular in the United States. For surgeons, who control the robot while sitting at a computer screen rather than standing over the patient, these operations can be less tiring. Plus robot hands don't shake. Advocates say patients sometimes have less bleeding and often are sent home sooner than with conventional laparoscopic surgeries and operations involving large incisions. But the Food and Drug Administration is looking into a spike in reported problems during robotic surgeries. Earlier this year, the FDA began a survey of surgeons using the robotic system. The agency conducts such surveys of devices routinely, but FDA spokeswoman Synim Rivers said the reason for it now 'is the increase in number of reports received' about da Vinci. Reports filed since early last year include at least five deaths. Whether there truly are more problems recently is uncertain. Rivers said she couldn't quantify the increase and that it may simply reflect more awareness among doctors and hospitals about the need to report problems. Doctors aren't required to report such things; device makers and hospitals are. Company spokesman Geoff Curtis said intuitive Surgical has physician-educators and other trainers who teach surgeons how to use the robot. But they don't train them how to do specific procedures robotically, he said, and that it's up to hospitals and surgeons to decide 'if and when a surgeon is ready to perform robotic cases.' A 2010 New England Journal of Medicine essay by a doctor and a health policy analyst said surgeons must do at least 150 procedures to become adept at using the robotic system. But there is no expert consensus on how much training is needed. New Jersey banker Alexis Grattan did a lot of online research before her gallbladder was removed last month at Hackensack University Medical Center. She said the surgeon's many years of experience with robotic operations was an important factor. She also had heard that the surgeon was among the first to do the robotic operation with just one small incision in the belly button, instead of four cuts in conventional keyhole surgery.

阅读理解 This issue of Science contains announcements for more than 100 different Gorgon Research Conferences, on topics that range from atomic physics to developmental biology. The brainchild(某人的主意) of Nell Gordon of Johns Hopkins University, these week-long meetings are designed to promote intimate, informal discussions of frontier science. Often confined to fewer than 125 attendees, they have traditionally been held in remote places with minimal distractions. Beginning in the early 1960s, I attended the summer Nucleic Acids Gordon Conference in rural New Hampshire, sharing austere (简朴的) dorm facilities in a private boy's school with randomly assigned roommates. As a beginning scientist, I found the question period after each talk especially fascinating, providing valuable insights into the personalities and ways of thinking of many senior scientists whom I had not encountered previously. Back then, there were no cell-phones and no Internet, and all of the speakers seemed to stay for the entire week. During the long, session-free afternoons, graduate students mingled freely with professors. Many lifelong friendships were begun, and—as Gordon intended—new scientific collaborations began. Leap forward to today, and every scientist can gain immediate access to a vast store of scientific thought and to millions of other scientists via the Internet. Why, nevertheless, de in-person scientific meetings remain so valuable for a life in science? Part of the answer is that science works best when there is a deep mutual trust and understanding between the collaborators, which is hard to develop from a distance. But most important is the critical role that face-to-face scientific meetings play in stimulating a random collision of ideas and approaches. The best science occurs when someone combines the knowledge gained by other scientists in non-obvious ways to create a new understanding of how the world works. A successful scientist needs to deeply believe, whatever the problem being tackled, that there is always a better way to approach that problem than the path currently being taken. The scientist is then constantly on the alert for new paths to take in his or her work, which is essential for making breakthroughs. Thus, as much as possible, scientific meetings should be designed to expose the attendees to ways of thinking and techniques that are different from the ones that they already know.

阅读理解 Back in 1896, the Swedish scientist Svante Arrhenius realized that by burning coal we were adding carbon dioxide to the air, and that this would warm the Earth. But he mentioned the issue only in passing (顺便地), for his calculations suggested it would not become a problem for thousands of years. Others thought that the oceans would soak up any extra CO2, so there was nothing much to worry about. That this latter argument has persisted to this day in some quarters highlights our species' propensity (倾向) to underestimate the scale of our impact on the planet. Even the Earth's vast oceans cannot suck up CO2 as quickly as we can produce it, and we now know the stored CO2 is acidifying the oceans, a problem in itself. Now a handful of researchers are warning that energy sources we normally think of as innocuous could affect the planet's climate too. If we start to extract immense amounts of power from the wind, for instance, it will have an impact on how warmth and water move around the planet, and thus on temperatures and rainfall. Just to be clear, no one is suggesting we should stop building wind farms on the basis of this risk. Aside from the huge uncertainties about the climatic effects of extracting power from the wind, our present and near-term usage is far too tiny to make any difference. For the moment, any negative consequences on the climate are massively outweighed by the effects of pumping out even more CO2. That poses by far the greater environmental threat; weaning ourselves off fossil fuels should remain the priority. Even so, now it is the time to start thinking about the long-term effects of the alternative energy sources we are turning to. Those who have already started to look at these issues report weary, indifferent or even hostile reactions to their work. That's understandable, but disappointing. These effects may be inconsequential, in which case all that will have been wasted is some research time that may well yield interesting insights anyway. Or they may turn out to be sharply negative, in which case the more notice we have, the better. It would be unfortunate to put it mildly, to spend countless trillions replacing fossil-fuel energy infrastructure(基础建设) only to discover that its successor(替代物) is also more damaging than it need be. These climatic effects may even be beneficial. The first, tentative models suggest that extracting large amounts of energy from high-altitude jet streams would cool the planet, counteracting the effects of rising greenhouse gases. It might even be possible to build an energy infrastructure that gives us a degree of control over the weather: turning off wind turbines here, capturing more of the sun's energy there. We may also need to rethink our long-term research priorities. The sun is ultimately the only source of energy that doesn't end up altering the planet's energy balance. So the best bet might be invest heavily in improving solar technology and energy storage—rather than in efforts to harness, say, nuclear fusion. For the moment, all of this remains supposition(推测). But our species has a tendency to myopia. We have nothing to lose, and everything to gain by taking the long view for a change.

阅读理解 Women do not avoid fighting because they are dainty or scared, but because they have a greater stake than men in staying alive to rear their offspring. Women compete with each other just as tenaciously as men, but with a stealth and subtlety that reduces their chances of being killed or injured, says Anne Campbell of the department psychology at the University of Durham. Across almost all cultures and nationalities, men have a much smaller role than women in rearing children. 'Males go for quantity of children rather than quality of care for offspring, which means that the parental investment of women is much greater,' says Campbell. And unlike men, who can't be sure that their children have not been fathered on the sly by other men, women can always be certain that half an offspring's genes are theirs. Women have therefore evolved a strong impulse than men to see their children grow up into adults. Men's psychological approach is geared to fathering as many children as possible. To make this strategy work and to attract partners, men need to establish and advertise their dominance over rival males. Throughout evolution this has translated into displays of male aggression, ranging in scale from playground fights to world wars. Men can afford to take more risks because as parents they are more expendable. Women, meanwhile, can only ensure reproductive success by overseeing the development of their children, which means avoiding death. 'The scale of parental investment drives everything,' says Campbell. 'It's not that women are too scared to fight,' she says. 'It's more to do with the positive value of staying alive, and women have an awfully big stake not just in offspring themselves but in offspring they might have in the future,' she says. This means that if women do need to compete—perhaps for a partner—they choose low-risk rules of engagement. They use indirect tactics, such as discrediting rivals by spreading malicious rumors. And unlike men who glory in feats of dominance, women do better by concealing their actions and their 'victories'. But there is no doubt, says Campbell, that the universal domination of culture by males has exaggerated these differences in attitudes to physical aggression. 'The story we've always been told is that females are not aggressive,' says Campbell. And when they are aggressive, women are told that their behavior is 'odd or abnormal'.

阅读理解 Less meat and dairy in our diets could help reduce agricultural greenhouse gases by as much as 80% by 2055, according to a recent study by the Potsdam Institute for Climate Impact Research (PIK). The researchers created global land-use model to project likely outcomes given different scenarios involving consumer dietary trends and changes in agriculture production methods. The models take into consideration population growth, the world economy, and other factors. The researchers found that, if meat and dairy consumption patterns remain constant of increase, the associated global agricultural omissions will increase significantly. On the other hand, a 25% reduction over the next 40 years would help bring levels to where they were around 1995. Methane and nitrous oxide in particular could be reduced if less meat and dairy is produced and consumed. These gases are caused largely by livestock waste and synthetic fertilizers. Around two-thirds of nitrous-oxide emissions come from agriculture—and most of that as a result of either raising animals or producing the feed used to raise them. Consumers' food choices, combined with what one PIK researcher terms 'technical mitigation options on the producers side' could make an enormous impact on these emissions. While not nearly as much methane or nitrous oxide is released into the atmosphere as carbon dioxide, both are significantly more potent and they form substantial pieces of the greenhouse gas pie. Both of these gases trap heat and radiation in the atmosphere much more effectively than does carbon dioxide. The U.S. Environmental Protection Agency cites methane as being '21 times more effective at trapping heat in the atmosphere than carbon dioxide over a 100-year time period.' Nitrous oxide is more than 300 times more effective than CO2. While the PIK study doesn't detail exactly which consumer choices and eating habits can help reverse the trend, it seems clear that less is more when it comes to consuming meat and dairy products.

阅读理解 Just because you're better educated doesn't mean that you're any more rational than everyone else, no matter how hard you may try to give that impression. Take the selection of lottery numbers. A survey in Florida described at this year's annual meeting of the American Association for the Advancement of Science shows that better educated people try to use random number systems to pick their lottery numbers. Despite the apparent logic of choosing random numbers, however, their chances of winning are no better than those of ordinary folk who use birthdays, anniversaries and other 'lucky' dates. Nor are they better off than those who draw on omens and intuitions, picking numbers seen on car number-plates and in dreams. But no doubt they feel a lot more rational. That appearance of 'rationality' may be a dangerous thing. Scientists are not immune to subtle and subjective influences on their judgments. Take the data from a survey of the public and member of the British Society Of Toxicology discussed at the same meeting. The survey showed that most people agree with the view that animals can be used to help predict how human will react, to chemicals, and that if a chemical causes cancer in an animal, we can be 'reasonably sure' it will cause cancer in humans. The toxicologists, however, are more circumspect. They accept the first statement but less likely to agree that if a chemical causes cancer in an animal, it will do so in a human. Can this difference be attributed to their expertise? Perhaps. But consider the considerable variation among toxicologists, those who were young, female, working in academia rather than industry or who felt that technology is not always used for the good of all, were more likely to agree that what causes cancer in an animal will cause cancer in a human. Maybe we need to think more about how who we are affects our 'rational' decisions.

阅读理解 If you are reading this article, antibiotics have probably saved your life—and not once but several times. A rotten tooth, a knee operation, a brush with pneumonia; any number of minor infections that never turned nasty. You may not remember taking the pills, so unremarkable have these one-time wonder drugs become. Modern medicine relies on antibiotics—not just to cure diseases, but to augment the success of surgery, childbirth and cancer treatments. Yet now health authorities are warning, in uncharacteristically apocalyptic terms, that the era of antibiotics is about to end. In some ways, bacteria are continually evolving to resist the drugs. But in the past we've always developed new ones that killed them again. Not this time. Infections that once succumbed to everyday antibiotics now require last-resort drugs with unpleasant side effects. Others have become so difficult to treat that they kill some 25,000 Europeans yearly. And some bacteria now resist every known antibiotic. Regular readers will know why: New Scientist has reported warnings about this for years. We have misused antibiotics appallingly, handing them out to humans like medicinal candy and feeding them to livestock by the tonne, mostly not for health reasons but to make meat cheaper. Now antibiotic-resistant bacteria can be found all over the world—not just in medical facilities, but everywhere from muddy puddles in India to the snows of Antarctica(南极洲). How did we reach this point without viable successors to today's increasingly ineffectual drugs? The answer lies not in evolution but economics. Over the past 20 years, nearly every major pharmaceutical company has abandoned antibiotics. Companies must make money, and there isn't much in short-term drugs that should be used sparingly. So researchers have discovered promising candidates, but can't reach into the deep pockets needed to develop them. This can be fixed. As we report this week, regulatory agencies, worried medical bodies and Big Phar-ma are finally hatching ways to remedy this market failure. Delinking profits from the volume of drug sold (by adjusting patent rights, say, or offering prizes for innovation) has worked for other drugs, and should work for antibiotics—although there may be a worryingly long wait before they reach the market. One day, though, these will fall to resistance too. Ultimately, we need, evolution-proof cures for bacterial infection: treatments that stop bacteria from causing disease, but don't otherwise inconvenience the little blighters. When resisting drugs confers no selective advantage, drugs will stop breeding resistance. Researchers have a couple of candidates for such treatment. But they fear regulators will drag their feet over such radical approaches. That, too, can be fixed. We must not neglect development of the sustainable medicine we need, the way we have neglected simple antibiotic R D. If we do, one day another top doctor will be telling us that the drugs no longer work—and there really will be no help on the way.

阅读理解 When it comes to health, which is more important, nature or nurture? You may well think your genes are a more important predictor of health and ill health. Not so fast. In fact, it transpires that our everyday environment outweighs our genetics, big time, when it comes to measuring our risk of disease. The genome is out—welcome the exposome. 'The exposome represents everything a person is exposed to in the environment, that's not in the genes,' says Stephen Rappaport, environmental health scientist at the University of California, Berkeley. That includes stress, diet, lifestyle choices, recreational and medicinal drug use and infections, to name a few. 'The big difference is that the exposome changes throughout life as our bodies, diets and lifestyles change,' he says. While our understanding of the human genome has been growing at an exponential rate over the last decade, it is not as helpful as we hoped in predicting diseases. 'Genes only contribute 10 percent to the overall disease burden,' says Rappaport. 'Knowing genetic risk factors can prove absolutely futile ,' says Jeremy Nicholson at Imperial College London. He points to work by Nina Paynter at the Brigham and Women's Hospital in Boston, who investigated the effect of 101 genetic markers implicated in heart disease. After following over 19,000 women for 12 years, she found these markers were not able to predict anything about the incidence of heart disease in this group. On the other hand, the impact of environmental influences is still largely a mystery.' There's an imbalance between our ability to investigate the genome and the environment,' says Chris Wild, director of the International Agency for Research on Cancer, who came up with the idea of the exposome. In reality, most diseases are probably caused by a combination of the two, which is where the exposome comes in. 'The idea is to have a comprehensive analysis of a person's full exposure history,' says Wild. He hopes a better understanding of exposures will shed a brighter light on disease risk factors. There are likely to be critical periods of exposure in development. For example, the time from birth to 3 years of age is thought to be particularly important. 'We know that this is the time when brain connections are made, and that if you are obese by this age, you'll have problems as an adult,' says Nicholson.