单选题The problems of the elderly are attracting greater attention largely because the American population is growing steadily older as the proportion of its aged members increase. At the time of the first United States census in 1790, half of the people in the country were 16 or younger. By the turn of the present century the median age of the population had risen to 22.9 years; by 1970, it was 27.7 ; and by 1977 it had reached 28.9 ; the median age will reach 35 by the year 2000, and will approach 40 by the year 2030. In time the burden of the years affects even the healthiest individual. Aging is accompanied by physiological changes that are not necessarily the result of any disease: apart from the more obvious signs of age—such as baldness, wrinkling, changes in body form, and stiffness of limbs—there is a general process of atrophy of the cells and gradual degeneration. However, the rate of physiological aging varies greatly from one person to another. Some people show noticeable signs of aging as early as fifty. Others seem relatively young and vital at seventy, and may even continue to enjoy a vigorous sex life. In general, however, ill health becomes more common with advancing age. More than three quarters of those over sixty-five suffer from some chronic health condition. But ill health need not have only physiological causes; it can have social and psychological causes as well. People tend to follow social expectations to fill the roles that are offered to them. In a sense, all we offer the aged is a sick role—the role of the infirm person who has outlived his or her usefulness to society. An urbanized, industrialized society such as the United States is oriented toward youth, mobility, and activity. It does little to integrate the old into the social structure. Unlike the elders in a traditional society, the American aged can no longer lay automatic claim on their kin for support and social participation; on the contrary, they are more likely to have to try not to be a "nuisance" to their now independent adult offspring. Nor are they regarded as the wisest members of the community as the elders in a traditional society would be; instead, any advice they give is likely to be considered irrelevant in a changing world about which their descendants consider themselves much better informed. In America, childhood is romanticised, youth is idolised, middle age does the work, wields the power and pays the bills, and old age gets little or nothing for what it has already done. For many elderly Americans old age is a tragedy, a period of quiet despair, deprivation, desolation and muted rage. The tragedy of old age is not that each of us must grow old and die but that the process of doing so has been made unnecessarily painful, humiliating and isolating through insensitivity, ignorance, and poverty.

单选题Everybody loves a fat pay rise. Yet pleasure at your own can vanish if you learn that a colleague has been given a bigger one. Indeed, if he has a reputation for slacking, you might even be outraged. Such behaviour is regarded as "all too human," with the underlying assumption that other animals would not be capable of this finely developed sense of grievance. But a study by Sarah Brosnan and Frans de Waal of Emory University in Atlanta, Georgia, which has just been published in Nature, suggests that it is all too monkey , as well. The researchers studied the behaviour of female brown capuchin monkeys. They look cute. They are good-natured, co-operative creatures, and they share their food readily. Above all, like their female human counterparts, they tend to pay much closer attention to the value of "goods and services" than males. Such characteristics make them perfect candidates for Dr. Brosnan"s and Dr. de Waal"s study. The researchers spent two years teaching their monkeys to exchange tokens for food. Normally, the monkeys were happy enough to exchange pieces of rock for slices of cucumber. However, when two monkeys were placed in separate but adjoining chambers, so that each could observe what the other was getting in return for its rock, their behaviour became markedly different. In the world of capuchins, grapes are luxury goods (and much preferable to cucumbers). So when one monkey was handed a grape in exchange for her token, the second was reluctant to hand hers over for a mere piece of cucumber. And if one received a grape without having to provide her token in exchange at all, the other either tossed her own token at the researcher or out of the chamber, or refused to accept the slice of cucumber. Indeed, the mere presence of a grape in the other chamber (without an actual monkey to eat it) was enough to induce resentment in a female capuchin. The researchers suggest that capuchin monkeys, like humans, are guided by social emotions. In the wild, they are a co-operative, group-living species. Such cooperation is likely to be stable only when each animal feels it is not being cheated. Feelings of righteous indignation, it seems, are not the preserve of people alone. Refusing a lesser reward completely makes these feelings abundantly clear to other members of the group. However, whether such a sense of fairness evolved independently in capuchins and humans, or whether it stems from the common ancestor that the species had 35 million years ago, is, as yet, an unanswered question.

单选题Although it is the elderly and the young infants who get the siekest from the flu, it is young children who are most susceptible. In community flu outbreaks, it is not unusual for 30 to 40 percent of children to get the infection, perhaps twice the rate of adult infection. Flu spreads rapidly from child to child for a number of reasons. First, flu is spread by small respiratory droplets that are coughed or sneezed and float in the air. A well child can catch the flu from being in the same classroom or child care center with an ill child without them ever touching each other. (Contrast this with the way colds are usually spread, by large droplets on people's hands, making good hand washing an effective preventive strategy. )Also, flu appears to be contagious even the clay before symptoms begin, and because children don't get as sick as adults with the flu, they other stay in school or clay-care long enough to spread the disease to their classmates. While few otherwise healthy children have any serious consequences from the flu, it is these children that are the major conduit by which flu spreads through the community and into households. In ordinary households, adults are more frequently infected by children than by other adults. And it is adults with chronic diseases, and the elderly—particularly grandparents—that suffer the major consequences of this virus. One author has aptly referred to children as the "Typhoid Mary's" of the flu. Flu Vaccine is the best defense against the flu. It is recommended for all adults over the age of 65, or over the age of 50 if there are sufficient supplies, and for individuals of any age if they are at high risk. Those high risk individuals would include anyone with heart or lung disease, including asthma, and people with diabetes, chronic kidney disease or other chronic conditions. But recognizing that it is children who spread flu to households, it can be strongly argued to offer flu vaccine to healthy children who are in regular contact with other fanfily members who are at high risk by virtue of their age or underlying illnesses. This will help keep flu out of these households. Even if the grandparent has had flu vaccine, immunizing the grandchildren makes sense because flu vaccine is more reliably protective in younger healthier individuals. In addition, there are about 8 million children in the U. S. who have underlying conditions—most notably asthma—that make them eligible for flu vaccine. Regrettably, three out of four of these children end up ever getting the flu vaccine.

单选题We learn from the text that traffic planners are more concerned about

单选题According to experts, the test for AIDS is

单选题{{B}}Text 3{{/B}} Seven years ago, a group of female scientists at the Massachusetts Institute of Technology produced a piece of research showing that senior women professors in the institute's school of science had lower salaries and received fewer resources for research than their male counterparts did. Discrimination against female scientists has cropped up elsewhere. One study conducted in Sweden, of all places--showed that female medical-research scientists had to be twice as good as men to win research grants. These pieces of work, though, were relatively small-scale. Now, a much larger study has found that discrimination plays a role in the pay gap between male and female scientists at British universities. Sara Connolly, a researcher at the University of East Anglia's school of economics, has been analyzing the results of a survey of over 7 000 scientists and she has just presented her findings at this year's meeting of the British Association for the Advancement of Science in Norwich. She found that the average pay gap between male and female academics working in science, engineering and technology is around ￡ 1 500 ($ 2850 ) a year. That is not, of course, irrefutable proof of discrimination. An alternative hypothesis is that the courses of men's and women's lives mean the gap is caused by something else; women taking "career breaks" to have children, for example, and thus rising more slowly through the hierarchy. Unfortunately for that idea, Dr. Connolly found that men are also likely to earn more within any given grade of the hierarchy, Male professors, for example, earn over ￡ 4 000 a year more than female ones. To prove the point beyond doubt, Dr. Connolly worked out how much of the overall pay differential was explained by differences such as seniority, experience and age, and how much was unexplained, and therefore suggestive of discrimination. Explicable differences amounted to 77% of the overall pay gap between the sexes. That still left a substantia123% gap in pay, which Dr. Connolly attributes to discrimination. Besides pay, her study also looked at the "glass-ceiling" effect--namely that at all stages of a woman' s career she is less likely than her male colleagues to be promoted. Between postdoctoral and lecturer level, men are more likely to be promoted than women are, by a factor of between 1.04 and 2.45. Such differences are bigger at higher grades, with the hardest move of all being for a woman to settle into a professorial chair: Of course, it might be that, at each grade, men do more work than women, to make themselves more eligible for promotion. But that explanation, too, seems to be wrong. Unlike the previous studies, Dr. Connolly's compared the experience of scientists in universities with that of those in other sorts of laboratory. It turns out that female academic researchers face more barriers to promotion, and have a wider gap between their pay and that of their male counterparts, than do their sisters in industry or research institutes independent of universities. Private enterprise, in other words, delivers more equality than the supposedly egalitarian world of academia does.

单选题In the third paragraph the author uses the example of the single mother to indicate that faith

单选题We may infer from the passage that the author' s attitude towards the whole set-up is ______.

单选题In a purely biological sense, fear begins with the body"s system for reacting to things that can harm us—the so-called fight-or-flight response. "An animal that can"t detect danger can"t stay alive," says Joseph LeDoux. Like animals, humans evolved with an elaborate mechanism for processing information about potential threats. At its core is a cluster of neurons deep in the brain known as the amygdala. LeDoux studies the way animals and humans respond to threats to understand how we form memories of significant events in our lives. The amygdala receives input from many parts of the brain, including regions responsible for retrieving memories. Using this information, the amygdala appraises a situation—I think this charging dog wants to bite me—and triggers a response by radiating nerve signals throughout the body. These signals produce the familiar signs of distress: trembling, perspiration and fast-moving feet, just to name three. This fear mechanism is critical to the survival of all animals, but no one can say for sure whether beasts other than humans know they"re afraid. That is, as LeDoux says, "if you put that system into a brain that has consciousness, then you get the feeling of fear." Humans, says Edward M. Hallowell, have the ability to call up images of bad things that happened in the past and to anticipate future events. Combine these higher thought processes with our hardwired danger-detection systems, and you get a near-universal human phenomenon: worry. That"s not necessarily a bad thing, says Hallowell. "When used properly, worry is an incredible device," he says. After all, a little healthy worrying is okay if it leads to constructive action—like having a doctor look at that weird spot on your back. Hallowell insists, though, that there"s a right way to worry. "Never do it alone, get the facts and then make a plan." He says. Most of us have survived a recession, so we"re familiar with the belt-tightening strategies needed to survive a slump. Unfortunately, few of us have much experience dealing with the threat of terrorism, so it"s been difficult to get fact about how we should respond. That"s why Hallowell believes it was okay for people to indulge some extreme worries last fall by asking doctors for Cipro and buying gas masks.

单选题{{B}}Directions:{{/B}}Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C, and D on ANSWER SHEET 1. As one works with color in a practical or experimental way, one is impressed by two apparently unrelated facts. Color as seen is a mobile, changeable thing{{U}} (1) {{/U}}to a large extent on the relationship of the color{{U}} (2) {{/U}}other colors{{U}} (3) {{/U}}simultaneously. It is not{{U}} (4) {{/U}}in its relation to the direct stimulus which{{U}} (5) {{/U}}it. On the other hand, the properties of surfaces that give{{U}} (6) {{/U}}to color do not seem to change greatly under a wide variety of illumination color, usually (but not always) looking much the same in artificial light as in daylight. Both of these effects seem to be{{U}} (7) {{/U}}in large part to the mechanism of color{{U}} (8) {{/U}}. When the eye is{{U}} (9) {{/U}}to a colored area, there is an immediate readjustment of the{{U}} (10) {{/U}} of the eye to color in and around the area{{U}} (11) {{/U}}. This readjustment does not promptly affect the color seen but usually does affect the next area to which the{{U}} (12) {{/U}}is shifted. The longer the time of viewing, the higher the{{U}} (13) {{/U}}, and the larger the area, the greater the effect will be{{U}} (14) {{/U}}its persistence in the{{U}} (15) {{/U}}viewing situation. As indicated by the work of Wright and Schouten, it appears that, at{{U}} (16) {{/U}}for a first approximation, full adaptation takes place over{{U}} (17) {{/U}}time if the adapting source is moderately bright and the eye has been in{{U}} (18) {{/U}} darkness just previously. Also,{{U}} (19) {{/U}}of the persistence of the effect if the eye is shifted around from one object to another, all of which are at similar brightness or have similar colors, the adaptation will tend to become{{U}} (20) {{/U}}over the whole eye.

单选题Being smart is the most expensive thing we do. Not in terms of money, but in a currency that is vital to all living things: energy. One study found that newborn humans spend close to 90 percent of their calories on building and running their brains. (Even as adults, our brains consume as much as a quarter of our energy.) If, during childhood, when the brain is being built, some unexpected energy cost comes along, the brain will suffer. Infectious disease is a factor that may rob large amounts of energy away from a developing brain. A great deal of research has shown that average IQ varies around the world, both across nations and within them. Higher IQ predicts a wide range of important factors, including better grades in school, a higher level of education, better health, better job performance, higher wages, and reduced risk of obesity. So having a better understanding of variations in intelligence might yield a greater understanding of these other issues as well. In a study in 2010, it was found that, among all the factors that affect intelligence, infectious disease works as the best predictor of the bunch. A recent study by Christopher Hassall and Thomas Sherratt repeated the study using more sophisticated statistical methods, and concluded that infectious disease may be the only really important predictor of average national IQ. Support for this hypothesis comes not only from cross-national studies, but from studies of individuals. There have been many studies, for example, showing that children infected with intestinal worms have lower IQ later in life. Another study by Atheendar Venkataramani found that regions in Mexico that were the target of malaria eradication programs had higher average IQ than those that were not. In practical terms, however, this means that human intelligence is mutable. If differences in IQ across the world are largely due to exposure to infectious disease during childhood, then reducing exposure to disease should increase IQ. Despite the strength of the findings, the study was not without its limitations. The researchers did their best to control for the effects of education. But what they really needed was to repeat their analysis across regions within a single nation, preferably one with standardized, compulsory education. The nation they chose was the United States. Average IQ varies in the states. Again, infectious disease was an excellent predictor of average state IQ. The states with the five lowest average IQ all have higher levels of infectious disease than the states with the five highest average IQ, and the relationship was good across all of the states in between. So far, the evidence suggests that infectious disease is a primary cause of the global variation in human intelligence. Since this is a developmental cause, rather than a genetic one, it's good news for anyone who is interested in reducing global inequality associated with IQ. It will allow people interested in using this information to raise the IQ of people around the world to target their efforts most effectively and efficiently.

单选题The foremost motivation behind the low-power radio initiative was to______.

单选题For months the Japanese searched fitfully for the right word to describe what was happening. At the Bank of Japan, the nation's central bank, officials spoke of "an adjustment phase.' Prime Minister admitted only to "a difficult situation." The Economic Planning Agency, the government's record keeper, referred delicately to a "retreat." Then two weeks ago, for the first time since 1997, the agency dropped its boilerplate reference to the "expansion" from its closely watched Monthly Economic Report, and the word game was over. Japan's economy, the world's second largest, conceded the experts, was in recession. That admission confirmed the bad news businessmen had been reading in their spreadsheets for several months. "In 2001 one market after another turned bad," says Yoshihiko Wakamoto, senior vice president of Toshiba Corp., which now admits that its pretax profits for fiscal 2001, ending March 31, may be down a whopping 42%. In April, when many Japanese companies announce their results for 2001 fiscal year, most will report declining profits. Blue chips like Sony, NEC and Matsushita have all experienced drops of over 40% in pretax profits. Japan's security houses, hit by declining commissions from a falling stock market, will announce even more dramatic drops. Nomura Securities, once Japan's most profitable company, is talking about an 80% decline in profits. Auto manufacturers, banks, airlines, steel companies, department stores--all are in a slump. Technically, what is happening to the Japanese economy does not meet American criteria for a recession, normally defined as at least two consecutive quarters of negative growth. While economic growth has slowed in Japan, it has not ceased. Government economists are predicting a 3.5% increase in GNP for 2002. Outside experts are not so optimistic. But nearly everyone agrees that GNP growth in Japan is unlikely to slip into negative numbers, as it did last year in the U. S. and Britain. "There's no question that we are in a recession," pronounces Kunio Miyamoto, chief economist of the Sumitomo-Life Research Institute. "But it is a recession, Japanese-style." During the last half of the 1990s, Japanese companies based much of their expansion around the world on the wildly inflated values of the Tokyo Stock Exchange and Japan's frenzied real estate market. Now both those markets have collapsed. And with long-term interest rates up from 5% to 7%, Japanese companies are less able to sell vast quantities of high-quality goods at razor-thin profit margins. Added to this are pressures from shareholders for a greater return on investments, from Japan's trading partners for restraints on its aggressive trade practices, and from its own citizens for a reduction in their working hours so they can enjoy the fruits of 40 years of relentless toil.

单选题The journal Science is adding an extra round of statistical checks to its peer-review process, editor-in-chief Marcia McNutt announced today. The policy follows similar efforts from other journals, after widespread concern that basic mistakes in data analysis are contributing to the irreproducibility of many published research findings. "Readers must have confidence in the conclusions published in our journal," writes McNutt in an editorial. Working with the American Statistical Association, the journal has appointed seven experts to a statistics board of reviewing editors (SBoRE). Manuscript will be flagged up for additional scrutiny by the journal"s internal editors, or by its existing Board of Reviewing Editors or by outside peer reviewers. The SBoRE panel will then find external statisticians to review these manuscripts. Asked whether any particular papers had impelled the change, McNutt said: "The creation of the " statistics board" was motivated by concerns broadly with the application of statistics and data analysis in scientific research and is part of Science"s overall drive to increase reproducibility in the research we publish." Giovanni Parmigiani, a biostatistician at the Harvard School of Public Health, a member of the SBoRE group, says he expects the board to "play primarily an advisory role." He agreed to join because he "found the foresight behind the establishment of the SBoRE to be novel, unique and likely to have a lasting impact. This impact will not only be through the publications in Science itself, but hopefully through a larger group of publishing places that may want to model their approach after Science." John Ioannidis, a physician who studies research methodology, says that the policy is "a most welcome step forward" and "long overdue." "Most journals are weak in statistical review, and this damages the quality of what they publish. I think that, for the majority of scientific papers nowadays, statistical review is more essential than expert review," he says. But he noted that biomedical journals such as Annals of Internal Medicine, the Journal of the American Medical Association and The Lancet pay strong attention to statistical review. Professional scientists are expected to know how to analyze data, but statistical errors are alarmingly common in published research, according to David Vaux, a cell biologist. Researchers should improve their standards, he wrote in 2012, but journals should also take a tougher line, "engaging reviewers who are statistically literate and editors who can verify the process". Vaux says that Science"s idea to pass some papers to statisticians "has some merit, but a weakness is that it relies on the board of reviewing editors to identify "the papers that need scrutiny" in the first place."

单选题In the two decades between 1910 and 1930, over ten percent of the Black population of the United States left the South, where the majority of the Black population had been located, and migrated to northern states, with the largest number moving, it is claimed, between 1916 and 1918. It has been frequently assumed, but not proved, that most of the migrants in what has come to be called the Great Migration came from rural areas and were motivated by two concurrent factors: the collapse of cotton industry following boll weevil infestation, which began in 1898, and increased demand in the North for labor following the cessation of European immigration caused by the outbreak of the First World War in 1914. This assumption has led to the conclusion that the migrants' subsequent lack of economic mobility in the North is tied to rural background, a background that implies unfamiliarity with urban living and a lack of industrial skills. But the question of who actually left the South has never been investigated in detail. Although numerous investigations document a flight from rural southern areas to southern cities prior to the Great Migration, no one has considered whether the same migrants then moved on to northern cities. In 1910 over 600,000 Black workers, or ten percent of the Black work force reported themselves to be engaged in "manufacturing and mechanical pursuits", the federal census category roughly including the entire industrial sector. The Great Migration could easily have been made up entirely of this group and their families. It is perhaps surprising to argue that an employed population could be tempted to move, but an explanation lies in the labor conditions then prevalent in the South. About thirty-five percent of the urban Black population in the South was engaged in skilled trades. Some were from the old artisan class of slavery--blacksmiths, masons, carpenters--which had a monopoly of certain trades, but they were gradually being pushed out by competition, mechanization, and obsolescence. The remaining sixty-five percent, more recently urbanized, worked in newly developed industries--tobacco, lumber, coal and iron manufacture, and railroads. Wages in the South, however, were low, and Black workers were aware, through labor recruiters and the Black press, that they could earn more even as unskilled workers in the North than they could as artisans in the South. After the boll weevil infestation, urban Black workers faced competition from the continuing influx of both Black and White rural workers, who were driven to undercut the wages formerly paid for industrial jobs. Thus, a move north would be seen as advantageous to a group that was already urbanized and steadily employed, and the easy conclusion tying their subsequent economic problems in the North to their rural backgrounds comes into question.