Even though she was blind and deaf, Helen Keller was a woman with an extraordinary social vision. (46) When most women"s rights activists were working for the right to vote, Helen Keller advocated action that was more direct and more immediate than the vote. In 1911, speaking in England where women had the right to vote, she said: "Our democracy is but a name. We vote? What does that mean? It means that we choose between two bodies of real, though not avowed, autocrats. You ask for votes for women. (47) What good can votes do when ten-elevenths of the land of Great Britain belongs to 200,000 men and only one-eleventh to the rest of the 40,000,000? Have your men with their millions of votes freed themselves from this injustice?" (48) When she became active and openly socialist, a New York city newspaper, the Brooklyn Eagle, which had previously treated her as a heroine, criticized that her misguided socialism had somehow developed from her blind and deaf condition. She replied that when once she met the editor of the Brooklyn Eagle, he had complimented her lavishly: "But now that I have come out for socialism, he re minds me and the public that I am blind and deaf and especially liable to error." She added: "Oh, ridiculous Brooklyn Eagle! What an ungallant bird it is! (49) Socially blind and deaf, it defends an intolerable system, a system that is the cause of much of the physical blindness and deafness which we are trying to prevent. The Eagle and I are at war. I hate the system which it represents—When it fights back, let it fight fair...It is not fair fighting or good argument to remind me and others that I cannot see or hear. I can read. I can read all the socialist books I have time for in English, German and French. If the editor of the Brooklyn Eagle should read some of them, he might be a wiser man, and make a better newspaper. (50) If I ever contribute to the socialist movement, the book I sometimes dream of; I know what I shall name it: Industrial Blindness and Social Deafness".

You caught a cold yesterday, and feel extremely uncomfortable today. It is necessary to write a letter to your School Principal for a leave and tell him the reason for it: 1. inform your illness; 2. provide doctor"s certificate; 3. try to resume your study after recovery. You should write about 100 words. Do not sign your own name at the end of the letter. Use "Martin" instead. You do not need to write the address.

FlySheetAdvertisementWriteanessayof160-200wordsbasedonthedrawing.Inyouressay,youshould1)describethedrawingbriefly,2)explainitsintendedmeaning,and3)giveyourcomments.

A study found that the radiation from CT scans—the tests regularly used to【C1】______internal injuries or signs of cancer—is likely【C2】______for 2 percent of cancer cases in the United States. 【C3】______lots of Americans undergo CT scans, that research is unlikely to【C4】______in doctors" offices: Two-thirds of patients in a new JAMA study reported【C5】______nothing of the risks of the diagnostic procedure.【C6】______, 17 percent felt like they played an active role in a discussion【C7】______whether this diagnostic test was the best path forward. "Our study indicates that most decisions to undergo outpatient CT are【C8】______by physicians and risk communication is【C9】______," a team of researchers led by University of Colorado"s Tanner Caverly writes. "The risk communication that took place had limited【C10】______: respondents who recalled discussing the benefits and risks of imaging did not have better【C11】______." Would a conversation about the【C12】______risks have made a difference? Caverly"s team asked a few other questions that suggest it would: Patients undergoing the scan have little idea about the radiation【C13】______One-quarter self-identified radiation as a risk of a CT scan; 37 percent were able to identify CT scans as having a higher level of radiation【C14】______a chest x-ray. There"s a growing movement in medicine right now to【C15】______on unnecessary treatment or【C16】______of care. Much of this has been led by a group called Choosing Wisely, which has【C17】______with dozens of medical societies to come up with lists of【C18】______that doctors themselves don"t think they ought to be using. One of their key messages is that more care isn"t【C19】______better; all medicine comes with some level of risk That message does not,【C20】______, seem to be delivered in the doctor"s offices studied here.

Is athlete prowess attained or innate? Those who have suffered the scolding of a tyrannical games master at school might be forgiven for doubting the idea that anyone and everyone is capable of great sporting achievement, if only they would put enough effort into it. Practice may make perfect, but not all are built in ways that make it worth bothering in the first place. The latest evidence of this truth has been gathered by Sabrina Lee of Simon Fraser University in Vancouver and Stephen Piazza at Pennsylvania State University. They have looked at the anatomy of sprinters and found that their feet are built differently from those of couch potatoes. They looked at seven university splinters who specialize in the 100-metre dash and five 200-metre specialists, and compared them with 12 non-athletic university students of the same height. In particular, they looked at the sizes of bones of the toes and heel. They also used ultrasonic scanning to measure the sliding motion of the Achilles tendons(the tendon inside the back of your leg just above your heel)of their volunteers as their feet moved up and down. This allowed them to study the length of the lever created by the tendon as it pulls on the back of the heel to make the foot bend and push off the ground. Dr Lee and Dr Piazza found that the toes of their sprinters averaged 8.2cm in length, while those of non-sprinters averaged 7.3cm. The length of the lever of bone that the Achilles tendon pulls on also differed, being a quarter shorter in sprinters. These findings suggest sprinters get better contact with the ground by having longer toes. That makes sense, as it creates a firmer platform to push against. In a sprint race, acceleration off the block is everything. The reason for the difference in the Achilles tendons, though, is less immediately obvious. At first sight, sprinters might be expected to have more Achilles leverage than average, not less. First sight, however, is wrong. When muscles have to contract a long way, they usually do so quickly and with little force. When contracting short distances, though, they move more slowly and generate more force. Having a short Achilles lever allows the muscles that pull on the tendon to generate as much as 40% more force than the same muscles in a non-sprinter would be able to manage. It is possible—just—that these anatomical differences are the result of long and rigorous training., But it is unlikely. Far more probable is that the old saying of coaches, that great sprinters are born not made, is true. Everyone else, games masters included, should just get used to the idea.

If the opinion polls are to be believed, most Americans are coming to trust their government more than they used to. The habit has not yet spread widely among American Indians, who suspect an organization which has so often patronized them, lied to them and defrauded them. But the Indians may soon win a victory in a legal battle that epitomizes those abuses. Elouise Cobell, a banker who also happens to be a member of the Blackfeet tribe in Montana, is the leading plaintiff in a massive class-action suit against the government. At issue is up to $10 billion in trust payments owed to some 500,000 Indians. The suit revolves around Individual Indian Money (11M) accounts that are administered by the Interior Department"s Bureau of Indian Affairs (BIA). Back in the 1880s, the government divided more than 11m acres of tribal land into parcels of 80 to 160 acres that were assigned to individual Indians. Because these parcels were rarely occupied by their new owners, the government assumed responsibility for managing them. As the Indians" trustee, it leased the land out for grazing, logging, mining and oil drilling—but it was supposed to distribute the royalties to the Indian owners. In fact, officials admit that royalties have been lost or stolen. Records were destroyed, and the government lost track of which Indians owned what land. The plaintiffs say that money is owing to 500,000 Indians, but even the government accepts a figure of about 300,000. For years, Cobell heard Indians complain of not getting payment from the government for the oil-drilling and ranching leases on their land. But nothing much got done. She returned to Washington and, after a brush-off from government lawyers, filed the suit. Gale Norton, George Bush"s interior secretary was charged with contempt in November because her department had failed to fix the problem. In December, Judge Lam berth ordered the interior Department to shut down all its computers for ten weeks because trust-fund records were vulnerable to hackers. The system was partly restored last month and payments to some Indians, which had been interrupted resumed. And that is not the end of it. Ms Norton has proposed the creation of a new Bureau of Indian Trust Management, separate from the BIA. Indians are cross that she suggested this without consulting them. Some want the trust funds to be placed in receivership, under a, neutral supervisor. Others have called for Congress to establish an independent commission, including Indians, to draw up a plan for reforming the whole system. A messy injustice may at last be getting sorted out.

In 2010, a federal judge shook America' s biotech industry to its core. Companies had won patents for isolated DNA for decades—by 2005 some 20% of human genes were patented. But in March 2010 a judge ruled that genes were unpatentable. Executives were violently agitated. The Biotechnology Industry Organi-zation(BIO), a trade group, assured members that this was just a "preliminary step" in a longer battle. On July 29th they were relieved, at least temporarily. A federal appeals court overturned the prior decision , ruling that Muriad Genetics could indeed hold patents to two genes that help forecast a woman' s risk of breast cancer. The chief executive of Mytiad, a company in Utah, said the ruling was a blessing to firms and patients alike. But as companies continue their attempts at personalised medicine, the courts will remain rather busy. The Myriad case itself is probably not over. Critics make three main arguments against gene patents: a gene is a product of nature, so it may not be patented; gene patents suppress innovation rather than reward it; and patents' monopolies restrict access to genetic tests such as Myriad' s. A growing number seem to agree. Last year a federal task-force urged reform for patents related to genetic tests. In October the Department of Justice filed a brief in the Myriad case, arguing that an isolated DNA molecule "is no less a product of nature ... than are cotton fibres that have been separated from cotton seeds." Despite the appeals court's decision, big questions remain unanswered. For example, it is unclear whether the sequencing of a whole genome violates the patents of individual genes within it. The case may yet reach the Supreme Court. As the industry advances, however, other suits may have an even greater impact. Companies are unlikely to file many more patents for human DNA molecules—most are already patented or in the public domain. Firms are now studying how genes interact, looking for correlations that might be used to determine the causes of disease or predict a drug's efficacy. Companies are eager to win patents for "connecting the dots," explains Hans Sauer, a lawyer for the BIO. Their success may be determined by a suit related to this issue, brought by the Mayo Clinic, which the Supreme Court will hear in its next term. The BIO recently held a convention which included sessions to coach lawyer on the shifting landscape for patents. Each meeting was packed.

It may not be obvious, but hearing two languages regularly during pregnancy puts infants on the road to bilingualism by birth. According to new findings in Psychological Science, a journal of the Association for Psychological Science, infants born to bilingual mothers exhibit different language preferences than infants bom to mothers speaking only one language. Psychological scientists Krista Byers-Heinlein and Janet F. Werker from the University of British Columbia along with Tracey Burns of the Organization for Economic Co-operation and Development in France wanted to investigate language preference and discrirnination in newborns. Two groups of newborns were tested in these experiments: English monolinguals (whose mothers spoke only English during pregnancy) and Tagalog-English bilinguals (whose mothers spoke both Tagalog, a language spoken in the Philippines, and English regularly during pregnancy). The researchers employed a method known as "high-amplitude sucking-preference procedure" to study the infants" language preferences.This method capitalizes on the newborns" sucking reflex—increased sucking indicates interest in a stimulus. In the first experiment, infants heard 10 minutes of speech, with every minute alternating between English and Tagalog. Results showed that English monolingual infants were more interested in English than Tagalog—they exhibited increased sucking behavior when they heard English than when they heard Tagalog being spoken. However, bilingual infants had an equal preference for both English and Tagalog. These results suggest that prenatal bilingual exposure may affect infants" language preferences, preparing bilingual infants to listen to and learn about both of their native languages. To learn two languages, bilingual newborns must also be able to keep their languages apart. To test if bilingual infants are able to discriminate between their two languages, infants listened to sentences being spoken in one of the languages until they lost interest. Then, they either heard sentences in the other language or heard sentences in the same language, but spoken by a different person. Infants exhibited increased sucking when they heard the other language being spoken. Their sucking did not increase if they heard additional sentences in the same language. These results suggest that bilingual infants, along with monolingual infants, are able to discriminate between the two languages, providing a mechanism from the first moments of life that helps ensure bilingual infants do not confuse their two languages. The researchers observe that, "Monolingual newborns" preference for their single native language directs listening attention to that language" and that, "Bilingual newborns" interest in both languages helps ensure attention to, and hence further learning about, each of their languages." Discrimination of the two languages helps prevent confusion. The results of these studies demonstrate that the roots of bilingualism run deeper than previously imagined, extending even to the prenatal period.

Inthissectionyouareaskedtowriteacompositionof160-200wordsabout"WhereDoYouThinktheGraduatesShouldWork—inBigCitesorRuralAreas?"Youshouldwriteaccordingtotheoutlineandcartoongivenbelow.PleasewriteitclearlyontheANSWERSHEET.Requirements:1)describethefollowingcartoon;2)giveyourcomments.

Students'Self-careAbilityWriteanessayof160-200wordsbasedonthedrawing.Inyouressay,youshould1)describethedrawingbriefly,2)explainitsintendedmeaning,and3)giveyourcomments.

Eating healthily costs about $1.50 more per person daily, according to the most thorough review yet of the affordability of a healthy diet. "For many low-income families, an【C1】______$1.50 daily is quite a lot," says Mayuree Rao, "It【C2】______to about $550 more per year per person, and that could be a real【C3】______to healthy eating." Rao and her colleagues reached their【C4】______after analysing 27 studies from 10 high-income countries, comparing price【C5】______for healthy versus unhealthy ingredients and diets.【C6】______one study compared the cost of a diet rich in fruit and vegetables versus one that was【C7】______in them. Another compared prices of【C8】______healthy and less healthy items, such as wholegrain versus white bread. Individual items were【C9】______matched in price. Meats【C10】______the largest difference: healthier options cost an average of 29 cents per serving more than unhealthy options. 【C11】______this, comparisons of whole diets showed that healthier diets cost averagely $1.48 more per day. This shows that comparisons based on single ingredients don"t tell the full【C12】______. "It tells us that,【C13】______, it doesn"t cost more to eat healthier based on one nutrient," says Rao. "But there"s growing evidence that the【C14】______of foods in your diet【C15】______your disease risk more than any single nutrient, so we think our【C16】______finding that healthier diets cost about $1.50 more has the most public health【C17】______." As to why healthier food has become more【C18】______Rao says that it may be because the food industry organizes itself and the types of food it produces to【C19】______its own economies of scale,【C20】______than what"s best for consumers.

能源危机及影响 ——1991年英译汉及详解 The fact is that the energy crisis, which has suddenly been officially announced, has been with us for a long time now, and will be with us for an even longer time. Whether Arab oil flows freely or not, it is clear to everyone that world industry cannot be allowed to depend on so fragile a base.【F1】 The supply of oil can be shut off unexpectedly at any time, and in any case, the oil wells will all run dry in thirty years or so at the present rate of use. 【F2】 New sources of energy must be found, and this will take time, but it is not likely to result in any situation that will ever restore that sense of cheap and plentiful energy we have had in the times past. For an indefinite period from here on, mankind is going to advance cautiously, and consider itself lucky that it can advance at all. To make the situation worse, there is as yet no sign that any slowing of the world"s population is in sight. Although the birth-rate has dropped in some nations, including the United States, the population of the world seems sure to pass six billion and perhaps even seven billion as the twenty-first century opens. 【F3】 The food supply will not increase nearly enough to match this, which means that we are heading into a crisis in the matter of producing and marketing food. Taking all this into account, what might we reasonably estimate supermarkets to be like in the year 2001? To begin with, the world food supply is going to become steadily tighter over the next thirty years— even here in the United States. By 2001, the population of the United States will be at least two hundred fifty million and possibly two hundred seventy million, and the nation will find it difficult to expand food production to fill the additional mouths.【F4】 This will be particularly true since energy pinch will make it difficult to continue agriculture in the high-energy American fashion that makes it possible to combine few farmers with high yields. It seems almost certain that by 2001 the United States will no longer be a great food-exporting nation and that, if necessity forces exports, it will be at the price of belt-tightening at home. In fact, as food items will tend to decline in quality and decrease in variety, there is very likely to be increasing use of flavouring additives.【F5】 Until such time as mankind has the sense to lower its population to the point where the planet can provide a comfortable support for all, people will have to accept more "unnatural food".

TeachChildreninAccordancewithTheirAptitudeWriteanessayof160-200wordsbasedonthedrawing.Inyouressay,youshould1)describethedrawingbriefly,2)interpretitsintendedmeaning,and3)giveyourcomments.

You are going to read a list of headings and a text about science. Choose the most suitable heading from the list for each numbered paragraph. The first paragraph of the text is not numbered. There is one extra heading which you don"t need to use.A. The Need for ScienceB. The Methods of ScienceC. The Challenge of Unsolved ProblemsD. The Specific Features of the Laws of ScienceE. The Steps in Establishing a Scientific TheoryF. The Rapid Increase of Scientific Knowledge It is the business of the scientist to accumulate knowledge about the universe and all that is in it, and to find, if he is able, common factors which underlie and account for the facts that he knows. He chooses, when he can, the method of the "controlled experiment". (41)______. In the course of his inquiries the scientist may find what he thinks is one common explanation for an increasing number of facts. The explanation, if it seems consistently to fit the various facts, is called a hypothesis. If a hypothesis continues to stand the test of numerous experiments and remains unshaken, it becomes a law. (42)______. The "laws" of science differ from the "laws" of a country in two ways. First, a scientific law is liable at any time to need modifying. This happens when a fact is discovered which seems to contradict what the "law" would lead one to expect. The "law" may, in fact, have to be abandoned altogether. Second, a scientific "law" says, "This is likely to be the explanation", or "This accounts for the facts as far as we know them". But the "law" of the country says, "You must..." or "You must not…" The scientific "law" has no moral force; it is not binding on human behavior nor approved or opposed by human conscience. (43)______. The evidence as to the vastness of the universe and the complexity of its arrangements continues to grow at an amazing rate. The gap between what we know and all that can be known seems not to diminish, but rather to increase with every new discovery. Fresh unexplored regions are forever opening out. The rapidity of the growth of scientific knowledge, in the nineteenth and twentieth centuries, is apt to give students and teachers the impression that no sooner is a problem stated than the answer is forthcoming. A more detailed study of the history of science corrects the impression that fundamental discoveries are made with dramatic suddenness. Even in our present age no less than fifty years separate the discovery of radioactivity from the explosion of the first atomic bomb. The teacher, giving his brief accounts of scientific discovery, is apt to forget the long periods of misunderstanding, of false hypotheses and general uncertainty, which almost invariably precede the clear statement of scientific truth. (44)______. The vast mass of information which scientists have gained has provided the answer to the fundamental questions which, through the centuries, have puzzled and sometimes tortured the human mind. There are many such questions. The study of parasites has provided evidence that organisms which could be self-supporting have become parasites, but hardly any light has been shed on the problem of why they should have done so. What enables an organism to respond to the poisonous secretions of harmful bacteria and organize its resources to defend its life? (45)______. To raise the standard of living in any country, two things are required: scientific knowledge, and a population sufficiently educated to understand how to apply it. Without the latter, the expected benefits will not come.Notes: ado麻烦，忙乱。be binding on对...有约束力。parasite 寄生虫。shed light on 使某事物更清楚些。secretion分泌物

The American economy is growing, according to the most recent statistics, at the sizzling rate of 7%, and is in the middle of the largest peacetime expansion in American history. We read in the newspapers that practically everyone who wants a job can get one. Microsoft is running advertisements in the New York Times practically begging Congress to issue more visas for foreign computer and information technology workers. In this environment, it is shocking that one group of Americans, people with disabilities, have such a high level of unemployment: 30% are not employed the same percentage as when the Americans with Disabilities Act became law. Not only did their employment and labor earnings fall during the recession of the early 1990s, but employment and earnings continued to fall during the long economic expansion that followed. Many of these people are skilled professionals who are highly marketable in today"s economy. Part of the problem is discrimination, and part recent court rulings favoring employers in ADA lawsuits. Discrimination against people with disabilities is, unfortunately, alive and well, despite the legal prohibitions against discrimination in hiring people with disabilities. 79% of disabled people who are unemployed cite discrimination in the workplace and lack of transportation as major factors that prevent them from working. Studies have also shown that people with disabilities who find jobs earn less than their co-workers, and are less likely to be promoted. Unfavorable court rulings have not been helpful, either. Research by law professor Ruth Colker of Ohio State University has shown that in the eight years after the ADA went into effect, employer-defendants prevailed in more than 93% of the eases decided by trial. Of the cases appealed, employers prevailed 84% of the time. Robert Burgdorf, Ir., who helped draft the ADA, has written, "legal analysis has proceeded quite a way down the wrong road". Disability activists and other legal scholars point out that Congress intended the ADA as a national mandate for the ending of discrimination against people-with disabilities. Instead, what has occurred, in the words of one writer, is that the courts "have narrowed the scope of the law, redefined "disability," raised the price of access to justice and generally deemed disability discrimination as not worthy of serious remedy". But perhaps the greatest single problem is the federal government itself, where laws and regulations designed to help disabled people actually provide an economic disincentive to work. As Sen. Edward Kennedy wrote, "the high unemployment rate among people receiving federal disability benefits is not because their federal benefits programs have "front doors that are too big", but because they have "back doors that are too small"".

【F1】 Americans no longer expect public figures, whether in speech or in writing, to command the English language with skill and gift, nor do they aspire to such command themselves. In his latest book, Doing Our Own Thing: The Degradation of Language and Music and Why We Should, Like, Care, John McWhorter, a linguist and controversialist of mixed liberal and conservative views, sees the triumph of 1960s counter-culture as responsible for the decline of formal English. Blaming the permissive 1960s is nothing new, but this is not yet another criticism against the decline in education.【F2】 Mr. McWhorter's academic speciality is language history and change, and he sees the gradual disappearance of "whom", for example, to be natural and no more regrettable than the loss of the case-endings of Old English. 【F3】 But the cult of the authentic and the personal, "doing our own thing," has spelt the death of formal speech, writing, poetry and music. While even the modestly educated sought an elevated tone when they put pen to paper before the 1960s, even the most well regarded writing since then has sought to capture spoken English on the page. Equally, in poetry, the highly personal, performative genre is the only form that could claim real liveliness. In both oral and written English, talking is triumphing over speaking, spontaneity over craft. Illustrated with an entertaining array of examples from both high and low culture, the trend that Mr. McWhorter documents is unmistakable. But it is less clear, to take the question of his subtitle, why we should, like, care.【F4】 As a linguist, he acknowledges that all varieties of human language, including nonstandard ones like Black English, can be powerfully expressive—there exists no language or dialect in the world that cannot convey complex ideas. He is not arguing, as many do, that we can no longer think straight because we do not talk proper. 【F5】 Russians have a deep love for their own language and carry large chunks of memorized poetry in their heads, while Italian politicians tend to elaborate speech that would seem old-fashioned to most English-speakers. Mr. McWhorter acknowledges that formal language is not strictly necessary, and proposes no radical education reforms—he is really grieving over the loss of something beautiful more than useful. We now take our English "on paper plates instead of china." A shame, perhaps, but probably an inevitable one.

Last week, you were treated warmly by Miss Wang, a friend of your sister, when you visited Hangzhou. Now write a letter of thanks to her. Your letter should include: 1) an expression of your gratitude, 2) offer to return the favor one day, 3) your expectation for her visiting. You should write about 100 words. Do not sign your own name at the end of the letter. Use "Li Ming" instead. Do not write the address.

The following paragraphs are given in a wrong order. You are required to reorganize these paragraphs into a coherent text by choosing from the list A—G. The first and the last paragraphs have been placed for yous.A. The strain of HIV that was discovered in Sydney intrigues scientists because it contains striking abnormalities in a gene that is believed to stimulate viral duplication. In fact, the virus is missing so much of this particular gene—known as nef, for negative factor—that it is hard to imagine how the gene could perform any useful function. And sure enough, while the Sydney virus retains the ability to infect T cells—white blood cells that are critical to the immune system"s ability to ward off infection—it makes so few copies of itself that the most powerful molecular tools can barely detect its presence.B. If this speculation proves right, it will mark a milestone in the battle to contain the late-20th century"s most terrible epidemic. For in addition to explaining why this small group of people infected with HIV has not become sick, the discovery of a viral strain that works like a vaccine would have far-reaching implications. "What these results suggest", says Dr. Barney Graham of Tennessee"s Vanderbilt University, "is that HIV is vulnerable and that it is possible to stimulate effective immunity against it".C. But as six years stretched to 10, then to 14, the anxiety of health officials gave way to astonishment. Although two of the recipients have died from other causes, not one of the man"s contaminated blood has come down with AIDS. More telling still, the donor is also healthy. In fact his immune system remains as robust as if he had never tangled with HIV at all. What could explain such unexpected good fortune?D. At the very least, the nef gene offers an attractive target for drug developers. If its activity can be blocked, suggests Deacon, researchers might be able to bring the progression of disease under control, even in people who have developed full-blown AIDS. The need for better AIDS-fighting drugs was underscored last week by the actions of a U.S. Food and Drug Administration advisory panel, which, recommended speedy approval of two new AIDS drugs. Although FDA commissioner David Kessler was quick to praise the new drugs, neither medication can prevent or cure AIDS once it has taken hold. What scientists really want is a vaccine that can prevent infection altogether. And that"s what makes the Sydney virus so promising—and so controversial.E. A team of Australian scientists has finally solved the mystery. The virus that the donor contracted and then passed on, the team reported last week in the journal Science, contains flaws in its genetic script that appear to have rendered it harmless. "Not only have the recipients and the donor not progressed to disease for 15 years", marvels molecular biologist Nicholas Deacon of Australia"s Macfarlane Burnet Centre for Medical Research, "but the prediction is that they never will". Deacon speculates that this "impotent" HIV may even be a natural inoculant that protects its carriers against more virulent strains of the virus.F. But few scientists are enthusiastic about testing the proposition by injecting HIV—however weakened—into millions of people who have never been infected. After all, they note, HIV is a retrovirus, a class of infectious agents known for their alarming ability to integrate their own genes into the DNA of the cells they infect. Thus once it takes effect, a retrovirus infection is permanent.G. About 15 years ago, a well-meaning man donated blood to the Red Cross in Sydney, Australia, not knowing he has been exposed to HIV-1, the virus that causes AIDS. Much later, public health officials learned that some of the people who got transfusions containing his blood had become infected with the same virus; presumably they were almost sure to die.Order: G is the first paragraph and F is the last.

After decades of exile from U.S. courts, the science of lie detection is gaining new acceptance. But the federal government wants to put a stop to it, and the U.S. Supreme Court has now agreed to consider a request from the Department of Justice to bar the technology from military courts. Uncertainties surround the science of lie detection, which uses a device called polygraph. In 1991 President George Bush banned lie detector evidence in military courts. But that ban has since been overturned by the U.S. Court of Military Appeals, which ruled that it restricts defendants" rights to present evidence of their innocence. In the past two years, some federal courts have also ruled that polygraph evidence can be heard. This follows a decision by the Supreme Court in 1993 that gave federal judges more discretion to decide on the admissibility of evidence. A polygraph consists of monitors for pulse rate, sweating and breathing rate. The device is supposed to uncover lies by recording increases in these measures as the subject answers questions. Critics have always argued that cunning defendants can control their physiological responses and sway polygraph results. But supporters of the technique argue that recent research has found it to be reliable. A psychologist named Charles Honts at a state university in Idaho, points to lab oratory studies, some of them being his own, in which student-subjects were offered cash to sway the test results. This argument is rejected by Leonard Saxe, a psychologist at a Boston university. "There is a huge difference between students in a lab and a defendant", he says. Guilty defendants have time in which to rehearse their lies, and can even come to believe them to be true. Saxe believes that the entire theoretical basis of lie detection is invalid. "It assumes you will be more nervous lying than telling the truth". But he says that for some people lies are trivial, while certain truth can be hard to swallow. David Faigrnan of the University of California says that if the Supreme Court upholds the military appeal court"s decision to allow polygraph evidence, polygraph bans would be overturned in federal courts across U.S. "That will put a big burden on judges to understand the science, and lead to a lot more" expert testimony in the courts", he predicts. The justice department fears that this will greatly increase the cost of trials.

The battle to prevent or at least slow global warming has intensified in the past year as scientists have learned more about the magnitude of the problem. One of the leading climate experts, Inez Y. Fung, director of the Atmospheric Sciences Center at the University of California, Berkeley, recently showed that the earth may soon lose its ability to absorb much of the greenhouse gas that israising temperatures. The oceans and continents currently soak up about half the carbon dioxide produced by the burning of fossil fuels. In the oceans, the gas combines with water to form carbonic acid; on land, plants take in more carbon dioxide and grow faster. But computer modeling done by Fung and her colleagues indicates that these carbon sinks will become less effective as the earth continues to warm. For example, as the tropics become hotter and drier in the summer, plants will reduce their respiration of carbon dioxide to avoid water loss. Atmospheric measurements over the past decade have confirmed this effect. If the oceans and land take in less carbon dioxide, more will remain in the atmosphere and global warming could accelerate catastrophically. Despite these warning signs, the government administration has opposed approval of the Kyoto Protocol, the international treaty mandating reductions in greenhouse gas emissions. But nine states in the northeastern U.S. are attempting to sidestep the federal government"s opposition by taking action on their own. Last August the group reached a preliminary agreement to reduce emissions of carbon dioxide by 10 percent by 2020. The plan requires approval by the state legislatures, but environmentalists are already hoping that other regions of the U.S. will follow suit. If adopted nationwide, the proposal would lower greenhouse gas emissions by roughly as much as the Kyoto Protocol would have. Steve Howard, chief executive of the Climate Group, is tackling the global-warming problem from a different angle. Founded in 2004, the Climate Group is a coalition of corporations and local governments that have voluntarily committed to reducing their greenhouse gas emissions. Members include oil giant BP (British Petroleum Co. PLC), drug-maker Johnson BP, for instance, slashed its energy bills by $650 million over 10 years. "We have seen important evidence about successful emission reduction scattered here and there in the most surprising places all over the globe," Howard says. "We are working to bring all of it together so that it forms a body of evidence."