Every day 25 milion U. S. children ride school buses. The safety record for these buses is much better than for passenger cars; but nevertheless, about 10 children are killed each year riding on large school buses, and nearly four times that number are killed outside buses in the loading zones. By and large, however, the nation"s school children are transported to and from school safely. Even though the number of school bus casualties(死亡人数) is not large, the safety of children is always of intense public concern. While everyone wants to see children transported safely, people are divided about what needs to be done—particularly whether seat belts should be mandatory (强制性的). Supporters of seat belts on school buses argue that seat belts are necessary not only to reduce death and injury, but also to teach children lessons about the importance of using them routinely in any moving vehicle. A side benefit, they point out, is that seat belts help keep children in their seats, away from the bus driver. Opponents of seat belt installation suggest that children are already well protected by the school buses that follow the National Highway Traffic Safety Administration"s (NHTSA) safety requirement set in 1977. They also believe that many children won"t wear seat belts anyway, and that they may damage the belts or use them as weapons to hurt other children. A new Research Council report on school bus safety suggests that there are alternate safety devices and procedures that may be more effective and less expensive. For example, the study committee suggested that raising seat backs four inches may have the same safety effectiveness as seat belts. The report sponsored by the Department of Transportation at the request of Congress, reviews seat belts extensively while taking a broader look at safety in and around school buses. Each year, children killed outside buses in the loading zones are about_______.A.10B.40C.30D.50

A.dated B.unlikely C.set D.fossils E.estimate F.delicateG.takes H.finds I.exactly J.advocated K.tracked Haul of Fossil Fish Pushes Back the Origin of Teeth and Jaws Our teeth and jaws are incredibly ancient.They're older than dinosaurs，older than arms and legs，older than trees adaptations that paleontologists （古生物学家） have （1） ____ to our distant，fishy relatives that thrived in the seas around 425 million years ago.But a collection of carefully-preserved vertebrates （脊椎动物） found in China has （2） ____ a new date for the earliest record of jaws and teeth.The early vertebrates include some of the earliest fish，one of the earliest relatives of sharks，and，at about 436 million years old，the most ancient （3） ____ yet found of fish with teeth and jaws. Researchers have disagreed about （4） ____ when the earliest bites evolved.Molecular （分子的） studies based upon estimations of genetic changes have （5） ____ that the first jaws and teeth evolved about 450 million years ago.Until now，the oldest fossil of jawed vertebrates-or gnathostomes （6） ____ to about 425 million years ago，a significant gap.As Institute of Vertebrate Paleontology and Paleoanthropology researcher Min Zhu and his colleagues describe in a series of Nature papers published today，the new （7） ____ from South China sit in the middle of this gap and offer a startling look at a critical moment in evolutionary history. Zhu and coauthors note in their research，the fish they uncovered were small and had （8） ____ bones.That means these fish were generally （9） ____ to become fossils except in truly outstanding circumstances where they could be buried quickly and shielded from scavengers （食腐动物） that would otherwise eat them.That an exceptional stroke of luck was required to preserve such fish likely explains the difference between the molecular （10） ____ and fossil record.

The competitive entrance examination for_to this university was such that hundreds of applicants were turned down each year.A. admitB. admittanceC. admissionD. permit

The term “parade”is __________ the Latin word “parare”, to prepare — in a military context — for war.A. incorporate ofB. part ofC. acquired fromD. derived from

I came home one day recently and， for reasons I don't quite understand， my living room smelled like my grandmother's house． Suddenly I felt as if I were 12 years old， happy and relaxed， sitting in her kitchen． I can remember what her house looked like， though it was sold 20 years ago --- her three-level plant stand， the plates lining the walls， the window over her sink-but these visual memories don't have the power that smell does． The funny thing is， I can't even begin to describe the odor （气味） that was so distinctively hers． The best I can do is this： "It smelled like my grandmother's house．" It's a common experience， and a common linguistic （语言学的） problem． In cultures worldwide， people have powerful olfactory-memories． This odor-memory link is also called "the Proust phenomenon，" after Marcel Proust's famous description of the feelings aroused by a cake dipped in tea in "Remembrance of Things Past．" Olfactory memories seem to be more closely bound up with emotions than are visual or auditory ones． Not all these memories are pleasant， of course， and smells can also trigger feelings of pain． It is surprisingly hard for English-speakers to describe the odors that occasion such strong emotions， however． English possesses almost no abstract smell words that pick out links or themes among unrelated aromas （芳香）， We have plenty of these in the visual field． "Yellow，" for example， identifies a characteristic that bananas， lemons， some cars， some flowers， old book pages， and the sun all share． But for odors， we don't have many more than the vague "musty" （smells old and stale） and "musky" （smells perfumery）． We usually have no choice but to say that one thing smells like another --- like a banana， like garlic， like diesel fuel． A few languages， though， do have a rich odor vocabulary． Linguist Asifa Majidhas found that the Jahai， the Semaq Beri， and the Maniq， hunter-gatherer groups in Malaysia and Thailand， employ a wide range of abstract smell words and can identify aromas as easily as we can colors． The Jahai have a word， for example， that describes "the seemingly dissimilar smell of petrol， smoke， bat poop， root of wild ginger and wood of wild mango．" Last year my cat got sprayed by a skunk （臭鼬）， and the vet told me to wash its face with coffee to cover the bad smell． Until then， I had never realized that coffee， which I find delicious， smells remarkably like skunk spray， which I do not． Science has identified the chemicals that both share． They are called mercaptans （硫醇）． But in oral English， we have no word for the underlying note that connects these two odors． If the Jahai drank coffee and encountered skunks， I bet they would．（1）The opening paragraph is mainly intended to ____ ．A． express the writer's affection for his grandmotherB． direct the readers' attention to a linguistic problemC． tell us the odor of the grandmother's house stayed the sameD． prove smell has a greater power than visual memories．（2）Which of the following is related to olfactory memories？ ____ A． Forming an image in mind after seeing the word "injury"．B． Feeling sympathetic when seeing a sick cat．C． Dancing to the music upon hearing it played．D． Missing fried eggs with garlic cooked by mum．（3）The example of the Jahai suggests that ____ ．A． the Jahai don't have many words in the visual fieldB． English possesses many vague words like "musty" and "musky"C． the Jahai has more abstract smell words than EnglishD． skunk and coffee have the same smell， but different functions（4）What can we learn from the passage？ ____ A． The author feels pity about the limitation of his language．B． English has a wide range of visual and odor vocabulary．C． Olfactory memories can bring nothing but pleasant feelings．D． Cultures worldwide always collide with each other．

Last year I bought a game for my children and I played it with them together．It troubled me that everyone won the game in the end．This seems like a perfect ending，but where's the incentive （刺激） to keep playing？We played the game twice in all，and it has been covered with dust there ever since．Without a possible winner，a game or contest loses its excitement．If there's nothing for one to compete for，the drive to do one's best is replaced by a"what's the meaning？"attitude．Competition is closely related to motivation．It's part of human nature to be competitive．A competitive spirit is the key to our success among our adults，so why not teach it in our children？I'm not suggesting we make our children compete against each other in heated competitions in all aspects of life．What I'm here to say is that we should pay attention to coaches（教练） who lose the spirit of good sportsmanship in the heated moment of the game．But in the right situations，a healthy competition can teach our kids a lot about life．While games and contests show the importance of drive and determination，they also teach our children how to deal with failure．And then come other good lessons-about learning from mistakes，searching for ways to improve and finding the will to try again．56．The author found that ____ ．A．the game interested them lotB．they had great fun playing the gameC．the game turned out to be less challengingD．the game gathered dust very easily57．What can we know from Paragraph 2？ ____ A．Humans are competitive by nature．B．Only adults have a competitive spirit．C．Only children have a competitive spirit．D．There is one possible winner in games．58．What does the underlined word"drive"in Para.2 mean？ ____ A．Power．B．Ability．C．Strength．D．Determination．59．In a healthy competition，children can learn the lessons except． ____ A．learning from mistakesB．giving up games and contestsC．having a try againD．finding ways to get improved60．What can we infer from the passage？ ____ A．Children should develop a competitive spirit in a game or contest．B．We should encourage children to compete in all aspects of life．C．Children should compete for nothing but prizes．D．Children must obey their coaches strictly in a game．

Towns and cities in Britain have grown a lot in size over the last two centuries. The-|||-oldest houses are usually those closest to the town center.Many people live in the suburbs,-|||-areas on the edge of a town.Some suburbs consist of new housing estates(住宅区),while-|||-others were originally villages that have become joined to the town as it has grown.-|||-Some people prefer to live in a village and travel into the nearby town to work. |a--|||-ges are considered to be pleasant places to live,as they are quieter and less polluted than-|||-towns and are closer to the countryside.They usually contain a range of houses,including-|||-old cottages and new houses and bungalows(小平房).-|||-Many British people prefer to buy a house rather than rent one,because they can dec--|||-orate or alter it to suit their own taste and because they believe they will have more priva-|||-cy.Young people and those who cannot afford to buy a house live in rented accommoda--|||-tion.Some rent a furnished bedsit (or bedsitting room ),a combined bedroom and sitting-|||-room,and share washing and cooking facilities. Others rent a flat or house,often sharing-|||-the cost with friends.-|||-Houses are bought and sold through estate agents. Few people can afford to buy a-|||-house outright(一次付清),so they have to take out a mortgage (=loan) with a bank or-|||-building society(房贷信用社)-|||-sbam tetil-|||-1.What do we learn about towns and cities in Britain?-|||-A)They are no longer as prosperous as two centuries ago.-|||-B) They have become more densely populated in recent years.-|||-C)They have grown ever bigger during the last two hundred years.-|||-D) They contain a range of houses the oldest of which are in downtown areas.-|||-2.Where do many people in Britain prefer to live?-|||-A)In the downtown areas.-|||-B)Near their workplaces.-|||-C)In remote villages.-|||-D)In the suburbs.-|||-conobneashin-|||-folblo-|||-3.Many British people prefer to buy a house rather than rent one,because __ -.-|||-A)they are now rich enough to buy it-|||-B) they want to enjoy a more independent life-|||-C)they hate to pay the increasingly high rent-|||-D)they can hardly settle down without a house of their own lessonn-|||-4.How do young people in Britain who cannot afford a house solve their housing problem?-|||-A)They share a room with a friend.-|||-B) They stay with their parents. zhunit sbietuo-|||-C)They take out a mortgage with a bank.-|||-D) They rent a room,a flat,or a house.-|||-1000019 10n-|||-28w li too botuion-|||-Read the following passages and choose the best answer to each of the multi--|||--choiee questions. do no to thamid mods boxlat avon od ,boldsaib dguort

Animal tests ―More than a cosmetic (化妆品) change Every time you reach for an eye-drop or reapply a lip salve, you do be so confident that the chemicals they contain are safe to use. But the toxicology (毒物学) tests on which regulators rely to gather this information are largely based on wasteful and often poorly predictive animal experiments. Efforts in Europe are about to change this, and the man charged with bringing toxicology into the twenty-first century is a plain-talking German: Thomas Hartung. Although Hartung acknowledges the immense challenges ahead, he sees this as an opportunity for toxicology "to turn itself at last into a respectable science". Three years ago, when Hartung became director of the European Centre for the Validation of Alternative Methods (ECVAM) in Ispra, Italy. ECVAM was set up in 1993 to support European Union policy aimed at reducing the number of animals used in regulatory testing. The centre, which sits on the sleepy shores of Lake Maggiore in the Italian Alps, originally had ten members of staff and faced an uphill struggle to cut back the millions of animal tests carried out in Europe every year. Then in 2003, two major policy changes were announced from above, increasing the pressure on the centre’’s labs. ECVAM found itself facing an unexpectedly short deadline for delivering a slew of animal-free methods for testing chemical toxicity.Rule change The first change was to the European Union’’s Cosmetics Directive, which phases out over ten years the use of animals in cosmetics testing. A short while later, the European Commission proposed its controversial REACH legislation (Registration, Evaluation and Authorization of Chemicals). Europe produces some 30,000 chemicals for which toxicity data have never been registered. REACH aims to make registration mandatory for both future and existing chemicals ― even those that have been on the market for decades. If, as expected, the REACH directive is approved next year, it will come into effect in 2007. Animal-welfare groups fear that this will mean millions more animals will be used in tests to meet the regulatory requirements. And industry claims that the testing process could cost billions of euros. Almost overnight, industry’’s interest in cheaper, animal-free testing skyrocketed. Last month ECVAM was put in charge of developing, with industry and regulatory agencies, the testing strategies for REACH. Now commanding 50 staff, Hartung is rising to the challenge. "The toxicity tests that have been used for decades are simply bad science", he explains. "We now have an opportunity to start with a clean slate and develop evidence-based tests that have true predictive value." Many of the animal tests used today were developed under crisis conditions. The notorious Draize test, which assesses the irritation or damage caused by chemicals simply by putting them into the eyes of rabbits, is a prime example. It was developed by the US Food and Drug Administration in 1944 after reports in the 1930s that some cosmetics were causing permanent eye injuries. One 38-year-old woman had gone blind after dyeing her lashes with Lash-Lure, a product that contained a derivative of coal tar. Then came the calamity of thalidomide (镇静剂), which was given to pregnant women in the late 1950s to control morning sickness, but which caused horrific birth defects. By this time, governments were highly sensitive to public concerns and called on their authorities to develop animal-based tests that would predict all conceivable toxic effects of drugs and chemicals. The principles behind most of those tests remain more or less unchanged today.Safety catch Each chemical that goes through the multiple tests required for registration can use up to 5,000 animals ― or 12,000 if the chemical is a pesticide. The cost of doing this for the 30,000 unregistered chemicals so that they comply with REACH has been estimated at between 5 billion (US6 billion) and 10 billion. In the decade since ECVAM was established, the number of animals used in toxicology testing has fallen slightly, although it still hovers at about one million per year. This reduction is a result of the refinement of existing tests, and the introduction of some alternative methods that rely on in vitro (试管) tests using cell cultures. ECVAM believes that it can halve the total number of animals used for regulatory testing within a decade. It has just completed its first large-scale validation study of an in vitro cytotoxicity test, which monitors death of cultured cells following short-term exposure to a chemical. Chemicals shown to be harmful in this test would be excluded from any LD50 animal tests. At least 70% of the chemicals registered in the past two decades fall into this category, says Hartung. And this is just the beginning.Poor prediction Most animal tests over-or under-estimate toxicity, or simply don’’t mirror toxicity in humans very well. The relevant industries also acknowledges the poor quality of those tests. Take the embryotoxicity test in which chemicals are fed to pregnant animals and the fates of their embryos, and the progeny of two subsequent generations, are studied. "Animal embryotoxicity tests are not reliably predictive for humans," says Horst Spielmann, a toxicologist at the Federal Institute for Risk Assessment in Berlin. "When we find that cortisone is embryotoxic in all species tested except human, what are we supposed to make of them " The same goes for cancer. To test a single chemical for its potential to cause cancer takes five years and involves 400 rats, each of which is treated with the maximum tolerated dose. It is dramatically over-predictive: more than 50% of the results are positive, of which 90% are false positive. Yet the number of compounds proved to be carcinogenic to humans is very low ― the International Agency for Research on Cancer in Lyons, France, has identified just 95 proven and 66 probable human carcinogens (致癌物质).Life or death Scientists also cannot assume that in vitro alternatives are automatically better, says Spielmann. In 1971, a comparison of animal Draize tests in different labs revealed the test to be hopelessly non-reproducible. But Spielmann’’s 1995 study of animal-free alternatives to the Draize test showed that they were equally unreliable. Since then the in vitro tests have been standardized, and they are intrinsically more reproducible. "Although reproducibility and relevance are not the same thing," Spielmann cautions. Relevance requires a good match between the test results and human data. At an ECVAM workshop in February, 30 industrial scientists met to develop the most effective strategy for using the alternative Draize tests, so that the false negatives and false positives of each test compensate for each other. This strategy is now going through the crucial validation procedure, in which human data, often from occupational health databases, will be used as points of reference. ECVAM has so far seen 17 alternative tests through validation ― 11 use in vitro methods, another six involve refining in vivo tests to reduce the number of animals used. Most of the new tests assess acute toxicity, but animal use is highest when testing for the toxic effects of prolonged exposure to chemicals for long-term consequences such as cancer and reproductive toxicity. These costly procedures are harder to mimic in vitro and may never be completely replaced.Sounds familial This is why, apart from the 30 million it uses to support ECVAM annually, the European Commission is funding three multimillion-euro ’’Integrated Projects’’. Under these, dozens of labs will collaborate for five years to tackle more difficult issues, such as allergic reactions (过敏反应) or widespread toxicity resulting from chemicals entering the bloodstream. Scientists know that they are likely to find it hardest to convince regulators about alternative tests for highly emotive issues such as cancer and birth defects. More than half of all animals that will be needed to support REACH legislation are likely to be used in reproductive toxicology testing. The 9-million Integrated Project called ReProTect has 27 labs dedicated to developing alternatives to these tests. The ReProTect consortium has broken down the human reproductive cycle into smaller elements, from male and female fertility to implantation, to pre-and postnatal development, and is trying to develop a meaningful package of tests. "Quite correctly everyone feels uneasy about taking risks where stakes are so high and issues so emotive," says Hartung. "We all want to be sure that there is real evidence that alternative tests are predictive of human toxicity." For example, regulators know the weaknesses of the rat cancer test as well as scientists but, wanting to be safe rather than sorry, they accept it because it is believed to throw up few false negatives. They prefer to let industry prove the innocence of any compound that shows up positive. Any replacement tests will need to reassure both regulators and industry.How is an embryotoxicity test carried out

【高三英语】阅读理解Junk food is everywhere. We’re eating way too much of it. Most of us know what we’re doing and yet we do it anyway. So here’s a suggestion offered by two researchers at the Rand Corporation: Why not take a lesson from alcohol control policies and apply them to where food is sold and how it’s displayed “Many policy measures to control obesity（肥胖症）assume that people consciously and rationally choose what and how much they eat and therefore focus on providing information and more access to healthier foods,” note the two researchers. “In contrast,” the researchers continue, “many regulations that don’t assume people make rational choices have been successfully applied to control alcohol, a substance — like food — of which immoderate consumption leads to serious health problems.” The research references studies of people’s behavior with food and alcohol and results of alcohol restrictions, and then lists five regulations that the researchers think might be promising if applied to junk foods. Among them: Density restrictions: licenses to sell alcohol aren’t handed out unplanned to all comers but are allotted（分配）based on the number of places in an area that already sell alcohol. These make alcohol less easy to get and reduce the number of psychological cues to drink. Similarly, the researchers say, being presented with junk food stimulates our desire to eat it. So why not limit the density of food outlets, particularly ones that sell food rich in empty calories And why not limit sale of food in places that aren’t primarily food stores Display and sales restrictions: California has a rule prohibiting alcohol displays near the cash registers in gas stations, and in most places you can’t buy alcohol at drive-through facilities. At supermarkets, food companies pay to have their wares in places where they’re easily seen. One could remove junk food to the back of the store and ban them from the shelves at checkout lines. The other measures include restricting portion sizes, taxing and prohibiting special price deals for junk foods, and placing warning labels on the products. 1. What does the author say about junk food A) People should be educated not to eat too much. B) It is widely consumed despite its ill reputation. C) Its temptation is too strong for people to resist. D) It causes more harm than is generally realized. 2. What do the Rand researchers think of many of the policy measures to control obesity A) They should be implemented effectively. B) They provide misleading information. C) They are based on wrong assumptions. D) They help people make rational choices. 3. Why do policymakers of alcohol control place density restrictions A) Few people are able to resist alcohol’s temptations. B) There are already too many stores selling alcohol. C) Drinking strong alcohol can cause social problems. D) Easy access leads to customers’ over-consumption. 4. What is the purpose of California’s rule about alcohol display in gas stations A) To effectively limit the density of alcohol outlets. B) To help drivers to give up the habit of drinking. C) To prevent possible traffic jams in nearby areas. D) To get alcohol out of drivers’ immediate sight. 5. What is the general guideline the Rand researchers suggest about junk food control A) Guiding people to make rational choices about food. B) Enhancing people’s awareness of their own health. C) Borrowing ideas from alcohol control measures.D) Resorting to economic, legal and psychological means. .

Towns and cities in Britain have grown a lot in size over the last two centuries. The-|||-oldest houses are usually those closest to the town center.Many people live in the suburbs,-|||-areas on the edge of a town.Some suburbs consist of new housing estates(住宅区),while-|||-others were originally villages that have become joined to the town as it has grown.-|||-Some people prefer to live in a village and travel into the nearby town to work. --|||-ges are considered to be pleasant places to live,as they are quieter and less polluted than-|||-towns and are closer to the countryside.They usually contain a range of houses,including-|||-old cottages and new houses and bungalows(小平房).-|||-Many British people prefer to buy a house rather than rent one,because they can dec-|||-orate or alter it to suit their own taste and because they believe they will have more priva-|||-cy.Young people and those who cannot afford to buy a house live in rented accommoda--|||-tion.Some rent a furnished bedsit (or bedsitting room ),a combined bedroom and sitting-|||-room,and share washing and cooking facilities.Others rent a flat or house,often sharing-|||-the cost with friends.-|||-Houses are bought and sold through estate agents. Few people can afford to buy a-|||-house outright(一次付清),so they have to take out a mortgage (=loan) with a bank or-|||-building society(房贷信用社).-|||-1.What do we learn about towns and cities in Britain?-|||-A)They are no longer as prosperous as two centuries ago-|||-B)They have become more densely populated in recent years.-|||-C)They have grown ever bigger during the last two hundred years.-|||-D) They contain a range of houses the oldest of which are in downtown areas.-|||-2.Where do many people in Britain prefer to live?-|||-A)In the downtown areas.-|||-B)Near their workplaces.-|||-C)In remote villages.-|||-D)In the suburbs.-|||-3.Many British people prefer to buy a house rather than rent one,because __-|||-A)they are now rich enough to buy it-|||-B) they want to enjoy a more independent life b-|||-C)they hate to pay the increasingly high rent-|||-D)they can hardly settle down without a house of their own-|||-4.How do young people in Britain who cannot afford a house solve their housing problem?-|||-A)They share a room with a friend.-|||-B)They stay with their parents.-|||-C)They take out a mortgage with a bank-|||-D)They rent a room,a flat,or a house.-|||-1on-|||-Read the following passages and choose the best answer to each of the multi--|||--choiee guestions.