单选题A finding in recent years shows that men cannot manufacture blood as efficiently as women can. This makes surgery riskier for men. Because they do not breathe as often as women, men also need more oxygen. But men breathe more deeply and this exposes them to another risk. They draw more of the air when it is polluted. Men's bones are larger than women's and they are arranged somewhat differently. The feminine walk that evokes so many whistles is a matter of bone structure. A man has broader shoulders and a narrower pelvis, which makes him stride out with no waste motion. A woman's wider pelvis, designed for childbearing, forces her to put more movement into each step she takes with the result that she displays a bit of jiggle and sway as she walks. If you think a man is brave because he can climb a ladder to clean out the roof gutters, don't forget it is easier for him than for a woman. The angle at which a woman's thigh is joined to her knees makes climbing difficult for her, no matter whether it is a ladder or stairs or a mountain that she is tackling. A man's skin is thicker than a woman's and not nearly as soft. This prevents the sun's radiation from getting through, which is why men wrinkle less than women do. Women have a thin layer of fat just under the skin and there is a plus to this greater fat reserve. It acts as an invisible fur coat to keep a woman warmer in the winter. Women also stay cooler in summer. Because the fat layer helps insulate them against heat. Men's fat is distributed differently. And they do not have that layer of it underneath their skin. In fact, they have considerably less fat than women and more lean mass. 41 percent of a man's body is muscle compared to thirty-five percent for women, which means that men have more muscle power. When we mention strength, almost 90 percent of a man's weight is strength compared to about 50 percent of a woman's weight. The higher proportion of muscle to fat makes it easier for men to lose weight. Muscle burns up five more calories a pound than fat does just to maintain itself. So when a man wants to loss weight, the pounds roll off much faster. For all men's muscularity they do not have the energy reserves women do. They have more start-up energy, but the fat tucked away in women's nooks and crannies provides a rich energy reserve that men lack. Cardiologists at the University of Alabama who tested healthy women on treadmills discovered that over the years the female capacity for exercise far exceeds the male capacity. A woman of sixty who is in good health can exercise up to 90 percent of what she could do when she was twenty. A man of sixty has only 60 percent left of his capacity as a twenty-year-old.

单选题 Early intelligence tests were not without their critics. Many enduring concerns were first raised by the influential journalist Walter Lippman, in a series of published debates with Lewis Terman, of Stanford University, the father of IQ testing in America. Lippman pointed out the superficiality of the questions, their possible cultural biases, and the risks of trying to determine a person's intellectual potential with a brief oral or paper-and-pencil measure. Perhaps surprisingly, the conceptualization of intelligence did not advance much in the decades following Terman's pioneering contributions. Intelligence tests came to be seen, rightly or wrongly, as primarily a tool for selecting people to fill academic or vocational niches. In one of the most famous -- if irritating -- remarks about intelligence testing, the influential Harvard psychologist E. G. Boring declared, "intelligence is what the tests test." So long as these tests did what they were supposed to do(that is, give some indication of school success), it did not seem necessary or prudent to probe too deeply into their meaning or to explore alternative views of the human intellect. Psychologists who study intelligence have argued chiefly about two questions. The first: Is intelligence singular, or does it consist of various more or less independent intellectual faculties? The purists -- ranging from {{U}}the turn-of-the-century{{/U}} English psychologist Charles Spearman to his latter-day disciples Richard J. Herrntein and Charles Murray -- defend the notion of a single overarching "g", or general intelligence. The pluralists -- ranging from L. L. Thurstone, of the University of Chicago, who posited seven vectors of the mind, to J. P. Guilford, of the University of Southern California, who discerned 150 factors of the intellect-construe intelligence as composed of some or even many dissociable components. The public is more interested in the second question: Is intelligence (or are intelligences) largely inherited.'? This is by and large a Western question. In the Confucian societies of East Asia individual differences in endowment are assumed to be modest, and differences in achievement are thought to be due largely to effort. In the West, however, many students of the subject sympathize with the view -- defended within psychology by Lewis Terman, among others -- that intelligence is inborn and one can do little to alter one's intellectual birthright. Studies of identical twins reared apart provide surprisingly strong support for the "heritability" of psychometric intelligence. That is, if one wants to predict someone's score on an intelligence test, the scores of the biological parents (even if the child has not had appreciable contact with them) are more likely to prove relevant than the scores of the adoptive parents. By the same token, the IQs of identical twins are more similar than the IQs of fraternal twins. And, contrary to common sense, the IQs of biologically related people grow closer in the later years of life.

单选题The phrase "the process" in the last sentence of paragraph three refers to ________.

单选题Sarada and her team are convinced that ______.

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单选题A British investigation has found flaws in London"s pre-war assessment of Iraqi"s weapons threat, but the report has cleared Prime Minister Tony Blair of deceiving the nation into going to var. The investigation, led by former British civil service chief Robin Butler, concludes that British intelligence officers were wrong to say that Iraq possessed weapons of mass destruction that could be deployed within 45 minutes. That finding was a key element in a British government document issued in September 2002 that helped persuade the public and parliament that Iraq must be disarmed. Mr. Butler told reporters Iraq had no deployable(可使用的)chemical or biological weapons at the time of the March 2003 invasion. "We say it would be an unwise person who reaches the conclusion that nothing will ever be found in Iraq. But I do distinguish between stocks of agent, and weapons," he said. "And we do conclude that Iraq did not have significant, if any, stocks of chemical or biological weapons in a state fit for deployment." The Butler report clears Prime Minister Blair of knowingly manipulating poor intelligence to win support for the invasion. Mr. Butler says no one in particular is responsible for the intelligence failures. "I think no single individual is to blame. This was a collective operation, in which there were the failures we"ve identified, "he said. "But as I"ve said, no, in my view, there was no deliberate attempt on the part of the government to mislead." Mr. Blair appeared in parliament shortly after the report"s release. He accepted responsibility for the intelligence mistakes, but said Saddam Hussein"s Iraq posed a threat that could not be ignored after the 2001 terrorist attacks against the United States. "I can honestly say I never have had to make a harder judgment. But in the end, my judgment was that after September 11th, we could no longer run the risk. That instead of waiting for the potential threat of terrorism and weapons of mass destruction to come together, we had to get out and get after it," he said. Mr. Blair brushed off suggestions from the opposition Conservative Party that his credibility has been damaged by Iraq, and that parliament would be less likely to trust him if asked again to vote to go to war. Mr. Blair pointed out that the Conservatives also had supported the invasion of Iraq, and continue to do so. The Butler commission was less critical of pre-war intelligence failures than a U.S. Senate report issued last week. Some leading senators have said President Bush probably would not have gotten the Senate"s support to invade Iraq if the poor intelligence assessments had been known at the time.

单选题 Learning science helps children to develop ways of understanding the world around them. For this they have to build up concepts which help them link their experiences together, they must learn ways of gaining and organizing information and of applying and testing ideas. This contributes not only to children's ability to make better sense of things around them, but prepares them to deal more effectively with wider decision-making and problem-solving in their lives. Science is as basic a part of education as numeracy and literacy, it daily becomes more important as the complexity of technology increases and touches every part of our lives. Learning science can bring a double benefit because science is both a method and a set of ideas, both a process and product. The processes of science provide a way of finding out information, testing ideas and see- king explanations. The products of science are ideas which can be applied in helping to understand new experiences. The word "can" is used advisedly here, it indicates that there is the potential to bring these benefits but no guarantee that they will be realized without taking the appropriate steps. In learning science the development of the process side and the product side must go hand in hand, they are totally interdependent. This has important implications for the kinds of activities children need to encounter in their education But before pursuing these implications, there are still two further important points which underline the value of including science in primary education. The first is that whether we teach children science or not, they will ha developing ideas about the world around from their earliest years. If these ideas are based on casual observation, non-investigated events and the acceptance of hearsay, than they are likely to be non-scientific. "everyday" ideas. There are plenty of such ideas around for children to pick up. My mother believed (and perhaps still does despite my efforts) that if the sun shines through the window on to the fire it puts the fire out, that cheese maggots f a common encounter in her youth when food was sold unwrapped) are made of cheese and develop spontaneously from it, that placing a lid on a pan of boiling water makes it boil at a lower temperature, that electricity travels more easily if the wires are not twisted. Similar myths still abound and no doubt influence children's attempts to make sense of their experience. As well as hearsay, left to themselves, children will also form some ideas which seem unscientific; for example, that to make something move requires a force but to stop it needs no force. All these ideas could easily be put to the test; children's science education should make children want to do it. Then they not only have the chance to modify their ideas, but they learn to be sceptical about so-called "truths" until these have been put to the test. Eventually they will realize that all ideas are working hypotheses which can never be proved right, but are useful as long as they fit the evidence of experience and experiment. The importance of beginning this learning early in children's education is twofold. On the one hand the children begin to realize that useful ideas must fit the evidence; on the other hand they are less likely to form and to accept everyday ideas which can be shown to be in direct conflict with evidence and scientific concepts. There are research findings to show that the longer the non-scientific ideas have been held, the more difficult they are to change. Many children come to secondary science, not merely lacking the scientific ideas they need, but possessing alternative ideas which are a barrier to understanding their science lessons. The second point about starting to learn science, and to learn scientifically, at the primary level is connect- ed with attitudes to the subject. There is evidence that attitudes to science seem to be formed earlier than to most other subjects and children tend to have taken a definite position with regard to their liking of the subject by the age of 11 or 12. Given the remarks just made about the clash between the non-scientific ideas that many children bring to their secondary science lessons and the scientific ideas they are assumed to have, it is not surprising that many find science confusing and difficult. Such reactions undoubtedly affect their later performance in science. Although there is a lesson here for secondary science, it is clear that primary science can do much to avoid this crisis at the primary/secondary interface

单选题Paul Johnson"s A History Of The American People is what we have come to expect from this productive writer—clear, colorful narrative, vivid character sketches, marvelous research, sweeping, confident statements, and an insistent conservative viewpoint which tempts him into serious omissions. He will not conceal his opinions, he tells us. Good. Then we can judge his history free of pretences to objectivity—his or ours. Almost at start, we notice something interesting: Johnson passes quickly over a defining moment in American history—the Columbus story—important because it is the first lesson every American schoolchild learns. How you treat that story—what you choose to tell of it—signals your view of the longer American experience, reaching to our time. In school textbooks, Columbus has always been presented as a hero. Only recently has a new set of facts—always available but ignored—begun to get into public attention: that Columbus, on landing, and desperate for gold, encountered native Americans who were peaceful and generous (by his own admission) and tortured them, kidnapped them, enslaved them, murdered them. Johnson, who goes into much detail about other matters (like Ronald Reagan"s jokes) is silent on this. Among his numerous references there is none to Bartolome de las Casas, an eyewitness, who described in detail the horrifying evils committed by Columbus and his fellowmen against the Indians, which resulted in the native population of Hispaniola being wiped out— genocide is an appropriate term—by the year 1550. I suggest this is not an innocent omission. Johnson wants us to look positively on the history of the United States. Yes, he says, there were "severe wrongs" committed in "the dispossession of a native people" and in the institution of slavery. But has the US, he asks at the start of his book, "made up for its organic sins"? His whole book suggests that it has, and that in doing so it has become (he says at the end) "a human achievement without parallel.., the first, best hope for the human race". Since Johnson has decided that the US is "the first, best hope for the human race", he has shaped its history accordingly. If we prefer to see that history as a complex and unfinished struggle of Americans for justice, against militarism, for economic, racial and sexual equality, we are badly served by a flattering admiration of those in power, pretending to be a history of "the people".

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单选题 It is easy to say letters are a (n){{U}} (21) {{/U}}way for family members to{{U}} (22) {{/U}}in touch when the children{{U}} (23) {{/U}}schools and jobs or{{U}} (24) {{/U}}families of their own. But what if you think letter writing is not your strong point? And your long-distance phone bill{{U}} (25) {{/U}}a national debt? Here are some advisable thoughts: Begin a post-card exchange. The message space is small but{{U}} (26) {{/U}}is the{{U}} (27) {{/U}}of home that counts. And it can be{{U}} (28) {{/U}}. Cards{{U}} (29) {{/U}}from the silly to the poetic; from seasonal scenes to famous paintings from art museums. Operate a clipping service. Envelopes{{U}} (30) {{/U}}with news items and cartoons are a welcome sight at mail call. Watch newspapers and magazines for articles that amuse or inform. You might{{U}} (31) {{/U}}a few brief comments in a note--soon you might be writing a whole letter. A daughter found a story about the joys (and hazards) of wallpapering a room and sent it to her mother with a written{{U}} (32) {{/U}}of her childhood memories of that experience in their own household. She discovered letter writing was easy when she{{U}} (33) {{/U}}her own experience. Send greeting cards which say "thinking of you." Busy young people find this an especially helpful way to fill the spaces between long, catching-up-to-news-letters. Use little note papers instead of lettersheet. Again, the writing space is small, but your thoughtfulness will be appreciated. Some organizations sell cards and notepapers as fund-raisers; for example, UNICEF{{U}} (34) {{/U}}money for the United Nations Children Fund with all-occasion cards and stationery designed by famous artists world-wide. This enables your message to do double to contact a loved one with{{U}} (35) {{/U}}to a cause. Send mementos from things you do. A theater program, a movie review from the newspaper--they can put into words that you want to say. Begin a photo-of-the-month exchange.{{U}} (36) {{/U}}the family album or take pictures of family faces and places. A mother sent her son of his childhood photos and found herself writing memories she had never shared. Her son, deeply{{U}} (37) {{/U}}, replied: "Send me more of my life history." Keep a{{U}} (38) {{/U}}. An executive wrote a paragraph a day before leaving his office and{{U}} (39) {{/U}}the paragraphs at the end of the week to his daughter. "At first it was pretty mundane," he said, "but soon I was looking for interesting things to write about and it became a real dialogue between us." Remember, it is not a skill with words that{{U}} (40) {{/U}}; it is the sight of an envelope from a family member.

单选题A rabid animal is most dangerous during the early stage of the disease because______.