Researchers have known that secondhand smoke can be just as dangerous for nonsmokers as smoking is for smokers, but now there’s fresh evidence quantifying just how hazardous the after-burn from cigarettes can be, and how quickly it affects your body. Scientists at the Oregon Department of Health documented for the first time an hourly buildup of a cancer- causing compound from cigarette smoke in the blood of nonsmokers working in bars and restaurants in the state. Reporting in the American Journal of Public Health, the researchers found that waitstaff and bartenders working a typical night shift gradually accumulated higher levels of NNK, a carcinogen in cigarette smoke, at the rate of 6% each hour they worked. NNK is known to be involved in inducing lung cancer in both lab rats and smokers. “We were somewhat surprised by the immediacy of the effect and the fact that we could measure the average hourly increase,“ says Michael Stark, the lead author of the study and a principal investigator at the Mulmomah County Health Department in Oregon. The authors are confident that the increases in NNK in the workers they tested most likely came from their exposure to smoke—the study included a control group of similar subjects in restaurants where no smoking was allowed. “There is experimental evidence from studies where you put nonsmokers in a room, blow smoke into the room and measure their artery function, that you see the platelets get sticky, which can cause clots and lead to a heart attack, and the ability of the arteries to dilate decreases very rapidly,“ says Dr. Matthew McKenna, director of the office on smoking and public health for the Centers for Disease Control. All of which could mean more time loitering outside buildings and in alleyways for smokers intent on grabbing a puff. Thirteen states now prohibit smoking in restaurants altogether (most of these include bars as well), and while 11 states still put no restrictions on lighting up, individual cities within those states—such as Austin in Texas, for example have passed legislation banning smoking in eating establishments and other public areas. It’s just getting harder to refute the scientific evidence; in a study done in Scotland several months after that nation instituted a ban on smoking in public places, researchers found that following the ban, bar patrons showed stronger lung capacity and reduced levels of inflammation (a red flag for a number of chronic diseases, including heart disease and asthma). “We made it pretty clear that the science on this is pretty irrefutable,“ says McKenna. And if smokers have fewer places to smoke, that message may finally get heard.

Alice kept getting the run-around every time she called the store manager about the digital camera she got the other day. Alice met the manager of a goods store when running around. The manager never got a call from Alice about the digital camera. Alice never got a satisfactory response from manager. The manger was running around the store when Alice took pictures.

They gave a house-warming party yesterday, but to be frank, their new apartment is no more comfortable than the former one. Their new house is warm, but not comfortable. The former house is close to a department store. They held a party to show their comfortable house. Neither apartment is comfortable.

The World Health Organization says extraordinary progress has been made since the global campaign to eradicate polio was launched in 1988. At that time, it says, 350 thousand children a year were paralyzed from this crippling disease. It says this figure dropped to 35 hundred last year. W-H-O Coordinator for the Global Polio Eradication Initiative, Bruce Aylward, says last year a record 550 million children under age five were immunized in 82 countries against polio. Although this is an important achievement, he says the job is not yet over. “The major challenge right now is to stop polio transmission everywhere within the next 24 months so that we can certify the world polio free on time in 2005. The greatest challenge to doing that will be making sure we access every child in the big remaining, heavily endemic or heavily infected polio areas.“ The World Health Organization says the polio virus is now present in no more than 20 countries. This is down from 125 in 1988. But, it notes immunizing children in these few remaining countries will not be easy. W-H-O says major difficulties lie in war-torn countries such as Afghanistan, Angola, the Democratic Republic of Congo, Somalia, and Sudan. But, it says problems also exist in polio-endemic countries such as Nigeria, Ethiopia, Pakistan, and Northern India. W-H-O vaccine export, Bjorn Melgaard says the goal is to be able to eventually stop immunizing children against polio. “Once we are absolutely certain that the virus is not spreading; that epidemics can no longer occur, that the containment has been achieved, then we can stop vaccination.“ Dr. Melgaard adds that the benefits from eradicating polio will be enormous. Besides ending the human suffering, he says countries will save about one-and-haft billion dollars a year in immunization costs. But the World Health Organization warns against complacency. It says the whole world is at risk of polio until the last polio virus is eradicated. This means everyone will have to remain vigilant and committed to achieving this major public health goal. Questions: 23.According to WHO coordinator, how soon shall we stop polio transmission everywhere so as to make the world polio free on time in 2005? 24.How many countries did they haste the polio virus in 1988? 25.What are the war-torn countries that WHO says major difficulties lie in? 26.What is the goal of this campaign? One year. Two years. Three years. Four years.

WOMAN: [furious] Imbecile! Idiot! Why didn’t you look where you were going? You ran into me just as I was mining into High Street. MAN: I’m very sorry; Madam, but you didn’t give a signal. WOMAN: Didn’t give a signal! I should think not indeed! I had the right of way. Don’t you know your Highway Code? MAN: Of course I do, Madam, but I’m sorry to say that when you came to the crossroads, you didn’t notice... WOMAN: I noticed all right—I noticed you were driving much too fast—positively dangerously. MAN: I’m afraid you’re making a mistake, Madam. As it happened, I’d just looked at my speedometer when I reached the crossroads and I was driving well below the speed limit. After all, this is a built-up area. WOMAN: You’d just looked at the speedometer? That shows you weren’t paying proper attention to the road, and just look what happened: you crashed into my car, you dented the bumper, you broke one of my headlamps, you scratched the bonnet, to say nothing of the fact that you terrified me so that I was completely speechless with fright! MAN: [surprised] Speechless, Madam? I’m sorry to hear that and I’d like to apologize for the damage: I did to your car. Nevertheless, if you’d been driving a little more carefully... WOMAN: Carefully! The whole thing was entirely your fault. I’d only come from the garage up the road. My car had just been serviced and I’d been collecting it. Of course I was driving carefully. MAN: I’m sure you thought you were driving with due care and attention, Madam, but I very much regret to tell you that you were exceeding the speed limit, and what’s more... WOMAN: Now just you listen to me! I wasn’t driving carelessly, I wasn’t driving too fast, my brakes were in perfect order, my windscreen was spotlessly clean, my tyres were in excellent condition, my driving mirror was angled correctly, but you... you... you... MAN: Me, Madam? WOMAN: You behaved most irresponsibly, driving straight over a crossroads like that without even looking to see if another car was coming. MAN: I’m sorry you think that, Madam, but the fact is the traffic lights were against you. They’d gone red just before you got to them. In the circumstances I’m afraid I must ask you for your name and address. WOMAN: My name and address! You give me yours first. MAN: With pleasure, Madam. Here’s my card? WOMAN: [reading aloud] “Inspector Robert Simpson—Downshire Police ...!“ But— but how was I to know you were a policeman? [Tearfully] You weren’t even wearing your uniform. MAN: Plain clothes duty, Madam. I was conducting a survey on the causes of road accidents in this area. Now, can I have your name and address please, Madam? Questions: 27.Where did the accident take place? 28.Why did the woman think her car was in good condition? 29.What was the real cause of the accident? 30.Why did the man want to see the woman’s driving license? At the crossroads. In a side street. On a highway. Just as the man was driving out of a lane.

We often hear and read about controversial issues in science and technology. For example, will radiation from electronic equipment【C1】______the environment? Should the DNA samples of【C2】______be put into a computer data base so investigators can compare it to the DNA of blood at【C3】______? Should medical scientists change gene structures to prevent【C4】______or to create more perfect human beings? While people are arguing about these and other【C5】______, technology continues to influence every aspect of everyday life—the home health and education,【C6】______, and so on. Some people carry on【C7】______with computers—their own or the ones available at【C8】______like cafes, social centers, libraries, and so on. Communicating with others on【C9】______or in【C10】______, computer users can get to know people they might never meet【C11】______Some look for【C12】______by computer: they might place【C13】______with photos on the screen or even produce【C14】______for their Websites. With【C15】______video connections, two people with cameras in their computers can see and talk to each other from【C16】______. With modern telephone technology, most people stopped writing letters-especially personal letters and notes. But now, writing to communicate has returned【C17】______, or email, which is a way of【C18】______from one computer to another. When a computer is ready to mail a letter, it【C19】______—that is, a central computer that collects and distributes electronic information. Delivery time from the sender to the receiver is no more than a few seconds, even from one country to another. For some computer users, the wish to【C20】______with others makes them want to write better.We often hear and read about controversial issues in science and technology. For example, will radiation from electronic equipment negatively change or destroy the environment? Should the DNA samples of convicted criminals be put into a computer data base so investigators can compare it to the DNA of blood at murder scenes? Should medical scientists change gene structures to prevent genetic diseases or to create more perfect human beings? While people are arguing about these and other controversial subjects, technology continues to influence every aspect of everyday life—the home health and education, entertainment and communication, and so on. Some people carry on active social lives with computers—their own or the ones available at terminals in public places like cafes, social centers, libraries, and so on. Communicating with others on electric bulletin boards or in chat rooms, computer users can get to know people they might never meet in traditional ways. Some look for potential dates or mates by computer: they might place personal ads with photos on the screen or even produce digitized video segments for their Websites. With live online video connections, two people with cameras in their computers can see and talk to each other from separate places. With modern telephone technology, most people stopped writing letters—especially personal letters and notes. But now, writing to communicate has returned in electronic form, or email, which is a way of sending messages from one computer to another. When a computer is ready to mail a letter, it dials a server—that is, a central computer that collects and distributes electronic information. Delivery time from the sender to the receiver is no more than a few seconds, even from one country to another. For some computer users, the wish to communicate intelligently or creatively with others makes them want to write better.

MAN: Yeah, I think the worst food I ever had was in France. WOMAN: Really? That’s odd. I thought the French were supposed to be really good cooks. MAN: Yes. that’s right. I suppose it’s Eke anywhere else though really. You know, some places are good. some are bad. Anyway, this was all our own fault really. WOMAN: Oh, what do you mean? MAN: Well, it was the first time I’d been to France—years ago this was when I was at school. I was in a coach party, actually, with some people—friends of my parents. My father’s a teacher you know, and these were all people from the school—they’d hired this coach to take them to Switzerland. WOMAN: A sort of school trip. MAN: That’s right. Safety in numbers I think, because most of them had never been abroad before. Anyway, I’d just started learning French at school, and I thought, great, you know, French is real. It’s a real place, real people. Anyway we’d crossed the Channel at night and we set off through France and at breakfast time we arrived and the coach driver had arranged for us to stop at this little cafe. We were absolutely exhausted, most of us—well, we’d been up most of the night being sea-sick. (WOMAN: Ugh!) Anyway, there we all were, tired and hungry and then we found out, the great discovery. WOMAN: What was that? MAN: The breakfast the coach driver had ordered was bacon and eggs. WOMAN: Oh fantastic! English tourists, My God! The real English breakfast. MAN: Yes, anyway we didn’t know any better—so we had it, and ugh...! WOMAN: What was it like? I think it’s pretty disgusting anyway, 1 must say. MAN: Oh, it was incredible. They just got a bowl and put some fat in it, I think. And then they put some bacon in the fat, broke an egg over the top and put the whole lot in the oven for about ten minutes. WOMAN: In the oven? You’re joking. You can’t cook bacon and eggs in the oven! MAN: Well. they must have done. It was hot, but it wasn’t cooked. There was just this egg floating about in gallons of fat and raw bacon. Delicious! WOMAN: Did you actually eat it? MAN: No, nobody did. They all wanted to turn round and go home. You know, back to teabags and fish and chips. You can’t blame them really. Anyway, the next night we were all given another foreign specialty. WOMAN: What was that? MAN: Snails—that really finished them off. Lovely holiday that was! Questions: 11.Where did the coach patty want to go? 12.Why were most tourists exhausted when they arrived in France the next morning? 13.What breakfast did the coach driver order for them? 14.What does the conversation imply? France. Switzerland. England. Spain.

WOMAN: Well, it’s pretty well laid out, I admit, and it’s sort of attractive, but in the end I still fred it a pretty depressing place. MAN: Do you? Why? WOMAN: Well, you know, the animals are out of their natural environment. They’re just here for humans to look at. There’s nothing natural about it. MAN: Yeah, but, if we didn’t have any zoos, a lot of species would just, well, they’d face extinction. WOMAN: Do you really believe that? MAN: Well, don’t you? I mean they have good breeding projects for some species that are dying out. Um, anyway, I think, there’s a trend towards developing zoos to become um... education centers, you know, stimulating information for kids and displays, and that kind of thing. WOMAN: Yeah, I know they’ve got lots of ideas, but these ideas are just because in the end, zoos axe outdated, aren’t they? Animals just don’t really want to breed in captivity. What we need to do is to take care of the natural environment, make sure that they’ve still got a place where they can live in the wild. MAN: Well, yeah, OK. But it’s just not happening, is it? I think in reality you’ve got to have zoos. WOMAN: Well, I just can’t agree with that. I mean, what is the pleasure in watching animals pacing uP and down in cages? MAN: Well, look, I mean, zoos are changing. OK. Some older zoos put animals in cages, but what about safari parks? You know, the animals are fine there. They’ve got a lot of Space and people see them in a much more natural setting. Um... I think people learn about them and they learn to respect animals. It’s probably, in the end, much better for animals that humans respect them in that way. WOMAN: Well, maybe you’re right. Questions: 19.What are the man and woman talking about? 20.Why does the mart think we still need zoos? 21.Where does the woman think is the right place for animal? 22.What kind of function does the man think that zoos and safari parks should serve? About the construction of the zoo. About the lay-out of the zoo. About the function of the zoo. About the attractiveness of the zoo.

3G mobile phone adopts the latest third generation wireless technology. 3G offers cell phone users high speed mobile internet access.

Few Americans stay put for a lifetime. They move from town to city to suburb, from high school to college in a different state, from a job in one region to a better job elsewhere, from the home where they raise their children to the home where they plan to live in retirement. With each move they are forever making new friends, who become part of their new life at that time.

In its everyday life, Italy is very much the man’s world. However, because of the Italian’s understanding of foreigners, the woman tourist is able to invade many of the male places that are prohibited to Italian women. These places include the caffe and the wine shop. In the large cities the caffe is a combination of club and office. Here, for the price of a coffee, an Italian can read all the newspapers brought to him. And he can transact business, with the waiter producing pen, ink, and stamps as needed. Or if he wants, he can sit outside under a canvas covering before the door and enjoy the sight of beautiful women passing by. The wine shop, as a rule, is a more vigorous place than the caffe, and is filled almost exclusively with men. Wandering singers, generally in groups of two or three, add to the noise of these places with their songs and music. Many of the songs are of a political character and make fun of the leading statesmen of Italy, America, England, France, and Russia. But the songs are generally showing off a spirit of mischief. And when the criticism is about America, the American tourists find themselves laughing as much as anyone else. The Italian is a master at making fun of you and making you like it. The Italian men are deep-rooted gamblers. They have been brought up to it as children, but they are cautious gamblers and never go too much in it. The national lottery used to be one of the most popular forms of gambling. But later a football stake had taken away much of the interest in the lottery. But here the important thing is that gambling, the same as drinking, seldom goes to an Italian’s head and his bets are not really dangerous risks. Even at cards the Italian plays for low stakes, generally for a cup of coffee or wine. In this world of the Italian male it would be careless if the romanticism of the Italian were neglected. The Italian might well be described as the world’s greatest romanticist. From any boat in Venice to any member of the government in Rome, the Italian is always aware of romance, of love and of the importance of being a good lover. On the beaches of Italy, the visitor is aware that the Italian really lives for romance. His manners, his compliments, his charm and his general way of behaving are those of a romanticist. Almost every Italian you meet is convinced that he is another Casanova. Romance is as much a part of Italy as its art and its history. Perhaps the feeling of romance that wells up in you when you come to Italy is one of the greatest things that Italy has to offer a world that is tired of war and political intrigue. It is the ideal place for a honeymoon because hotel managers and waiters make you conscious of your own love and stress it in such a way that you feel more in love in this country than in any other.

Middle born children will tell you that they usually didn’t feel all that special while growing up. The first born had his spot- carrier of the family banner and responsible for everything. The last born had his comfy little role, but the middle born had no distinctive place to call his own. Middle-borns just seem to be easily overlooked, and maybe that’s why there are so few pictures of them in the family photo album. There may be hundreds, seemingly thousands, of pictures of the firstborn. For some strange reason, however, which I have confirmed by polling middle-born children around the world, there are seldom many pictures of the middle child, and what photos there are have him included with the others—squeezed again between the older sibling and the younger sibling. Another thing that can be said of many middle-born children is that they typically place great importance on their peer group. The middle child is well known for going outside the home to make friends faster than anybody else in the family. When a child feels like a fifth wheel at home, friends become very important; as a result, many middle children (but not all, of course) tend to be the social lions of the family. While firstborns, typically, have fewer friends, middle children often have many. Middle children have a propensity to leave home first and live farther away from the family than anyone else. I observed a dramatic illustration of this tendency while I was a guest on Oprah Winfrey’s show. The subject that day was sibling rivalry. Three charming young women, all sisters, were among the guests, and we quickly learned that the firstborn and the last born were residents of the Eastern state where they had grown up. They had settled down near their parents and other family members. But the middle child had moved to the West Coast. I suppose she could have gotten another two thousand miles farther away by moving to Hawaii, but her point was still well made. Middle children are the ones who will most often physically distance themselves from the rest of the family. It’s not necessarily because they’re on the outs with everyone else. They simply like to do their own thing, make their own friends, and live their own lives. All of this is not to say that middle children totally ignore their siblings or the rest of the family. One common characteristic of the middle child is that she is a good mediator or negotiator. She comes naturally into this role because she’s often right in the middle, between big brother and little sister, whatever the case may be. And because she can’t have Mom or Dad all to herself, she learns the fine art of compromise. Obviously, these skills are assets in adult life, and middle children often become the best adjusted adults in the family.

Bernard Jackson is a free man today, but he has many bitter memories. Jackson spent five years in prison after a jury wrongly convicted him of raping two women. At Jackson’s trial, although two witnesses testified that Jackson was with them in another location at the times of the crimes, he was convicted anyway. Why? The jury believed the testimony of the two victims, who positively identified Jackson as the man who has attacked them. The court eventually freed Jackson after the police found the man who had really committed the crimes. Jackson was similar in appearance to the guilty man. The two women has made a mistake in identity. As a result, Jackson has lost five years of his life. The two women in this case were eyewitnesses. They clearly saw the man who attacked them, yet they mistakenly identified an innocent person. Similar incidents have occurred before. Eyewitnesses to other crimes have identified the wrong person in a police lineup or in photographs. Many factors influence the accuracy of eyewitness testimony. For instance, witnesses sometimes see photographs of several suspects before they try to identify the person they saw in a lineup of people. They can become confused by seeing many photographs or similar faces. The number of people in the lineup, and whether it is a live lineup or a photograph, may also affect a witnesses decision. People sometimes have difficulty in identifying people of other races. The questions the police ask witnesses also have an effect on them. Are some witnesses more reliable than others? Many people believe that police officers are more reliable than ordinary people. Psychologists decided to test this idea, and they discovered that it is not true. Two psychologists showed a film of crimes to both police officers and civilians. The psychologists found no difference between the police and the civilians in correctly remembering the details of the crimes. Despite all the possibilities for inaccuracy, courts cannot exclude eyewitness testimony from a trial. American courts depend almost completely on eyewitness testimony to resolve court cases. Sometimes it is the only evidence to a crime, such as rape. Furthermore, eyewitness testimony is often correct. Although people do sometimes make mistakes, many times they really do identify individuals correctly. American courts depend on the ability of the 12 jurors, and not the judges, to determine the accuracy of the witnesses testimony. It is their responsibility to decide if a certain witness could actually see, hear, and remember what occurred. In a few cases, the testimony of eyewitnesses has convicted innocent people. More importantly, it has rightly convicted a larger number of guilty people; consequently, it continues to be of great value in the American judicial system.

We have only to look behind us to get some sense of what may lie ahead. No one looking ahead 20 years possibly could have foreseen the ways in which a single invention, the chip, would transform our world thanks to its applications in personal computers, digital communications and factory robots. Tomorrow’s achievements in biotechnology, artificial intelligence or even some still unimagined technology could produce a similar way of dramatic changes. But one thing is certain: information and knowledge will become even more vital, and the people who possess it, whether they work in manufacturing or services, will have the advantages and produce the wealth; computer knowledge will become as basic a requirement as the ability to read and write. The ability to solve problems by applying information instead of performing routine tasks will be valued above all else. If you cast your mind ahead 10 years, information services will be predominant. It will be the way you do your job.

谁是你最景仰的人?据某一中学中开展的调查显示：40%的学生景仰科学家，35%的学生景仰体育、影视明星，只有1.5%的学生景仰自己的父母。为什么如此少的孩子景仰父母?许多孩子认为，父母没做什么惊天动地的大事，至于父母日常对他们的关怀照料，则被视为理所应当。一些教育专家认为，许多家长在任劳任怨的同时，盲目地关心孩子的学习成绩，容易造成孩子的冷漠和自私，缺乏感恩之心。长此以往，孩子永远不能真正懂得孝敬父母，理解他人，更不会主动帮助别人。父母应该让孩子知道，亲人对他们的付出不是理所应当的。

Health experts say washing your hands reduces the spread of viruses and other organisms that cause disease. This advice may sound simple. However, experts say a lot of people do not follow it. A recent study found that many Americans fail to wash their hands after using public toilets. About thirty percent of the people left public restrooms without stopping to wash their hands. In the study, researchers asked 1,000 adults how often they washed their hands. The researchers observed almost 8,000 people at public toilets in five major American cities. Remits of the study were compared to a similar study clone in 1996. More than ninety-five percent of Americans questioned said they always wash their hands after using public restrooms. However, the study found that only seventy percent of them actually do so. The study also found that American men arc less likely than women to wash their hands after using a public restroom. The American Society for Microbiology announced the findings. Judy Daly works for the group. She admits that hand washing may seem an unusual subject to study. But she says hand washing is a very serious issue. Experts say hand washing is the simplest and most effective way to reduce the spread of infectious diseases. Infections can spread by touching surfaces that have harmful organisms on them. Shaking hands with another person also can spread infection. Harmful bacteria may enter your body if you touch your mouth, nose or eyes. Among the most common infections spread by hand are colds, influenza, and throat and ear infections. In addition, millions of food poisoning cases each year are blamed on people who prepare food but do not wash their hands. More serious diseases like cholera and hepatitis are spread this way, too. Many patients in hospitals also get infections. Some die from them. The spread of infections often is blamed on health workers who do not wash their hand after treating patients. The American Society of Microbiology has launched a public information campaign to get more people to wash their hands. Experts say following the correct method is important. You should wash your hand with soap and hot running water for at least fifteen seconds. Questions: 15.Among the Americans questioned, how many of them don’t actually wash their hands after using public restrooms? 16.In the study, how many people were observed at public toilets in five major cities? 17.How do harmful bacteria enter your body? 18.How should you wash your hands? 13% 30% 67% 95%

I have just come home after viewing some astonishing works of art that were recently discovered in Church Hole cave in Nottinghamshire. They are not drawings, as one would expect, but etchings, and they depict a huge range of wild animals. The artists who created them lived around 13,000 years ago, and the images are remarkable on a variety of counts. First of all, their sheer number is staggering, there are ninety all told. Moreover, fifty-eight of them are on the ceiling. This is extremely rare in cave art, according to a leading expert, Dr Wilbur Samson of Central Midlands University. Wall pictures are the norm, he says, “But more importantly, the Church Hole etchings are an incredible artistic achievement. They can hold their own in comparison with the best found in continental Europe.“ I am not a student of the subject, so I have to take his word for it. However, you do not have to be an expert to appreciate their beauty. In fact, it is the wider significance of the etchings that is likely to attract most attention in academic circles, since they radically alter our view of life in Britain during this epoch. It had previously been thought that ice-age hunters in this country were isolated from people in more central areas of Europe, but the Church Hole images prove that ancient Britons were part of a culture that had spread right across the continent. And they were at least as sophisticated culturally as their counterparts on the mainland. An initial survey of the site last year failed to reveal the presence of the etchings. The reason lies in the expectations of the researchers. They had been looking for the usual type of cave drawing or painting, which shows up best under direct light. Consequently, they used powerful torches, shining them straight onto the rock face. However, the Church Hole images are modifications of the rock itself, and show up best when seen from a certain angle in the natural light of early morning. Having been fortunate to see them at this hour, I can only say that I was deeply—and unexpectedly—moved. While most cave art often seems to have been created in a shadowy past very remote from us, these somehow convey the impression that they were made yesterday. Dr Samson feels that the lighting factor provides important information about the likely function of these works of art. “I think the artists knew very well that the etchings would hardly be visible except early in the morning. We can therefore deduce that the chamber was used for rituals involving animal worship, and that they were conducted just after dawn as a preliminary to the day’s hunting.“ To which I can only add that I felt deeply privileged to have been able to view Church Hole. It is a site of tremendous importance culturally and is part of the heritage, not only of this country, but the world as a whole.

Every generation has its emblematic boy’s toy. Once upon a time there was the golf cart: a little toy car specifically designed for middle-aged men too rich to care about looking ridiculous. Later came the beach buggy, a briefly fashionable, wildly impractical, single-terrain vehicle. One might include the motorcycle or the snowmobile on this list, were they not, in certain contexts, quite useful, but there is no doubt which pointless recreational vehicle has captured the imagination of the landed, middle-aged celebrity: it’s the quad bike. What is it about this squat, ungainly, easy-to-flip machine that celebrities love so much? As recreational vehicles go, the quad bike is hardly sophisticated. They are to the countryside what the jet-ski is to Lake Windermere. “There’s nothing cool about a quad“, says Simon Tiffin, editor of a well-known magazine. “It’s a strange thing to want to hare round beautiful bits of the country in a petrol-guzzling machine.“ But celebrities love quad bikes. Musicians, comedians, DJs, actors and sportsmen have all been photographed aboard quads. “They’re the latest rich person’s toy“, says Tiffin. “Spoilt children get them for Christmas.“ Provided you~ ye got a large estate to go with it, however, the quad bike can remain a secret indulgence. You can go out and tear up your own piece of countryside without anyone knowing you’re doing it. The quad bike’s nonsensical name—“quad“ means four, but “bike“ is an abbreviation of “bicycle“, which means two—that comes to six—hints at its odd history. Originally the ATV, or all-terrain vehicle, as quads are sometimes known, was developed in Japan as a three-wheeled farm vehicle, an inexpensive mini-tractor that could go just about anywhere. In the 1980s the more stable four-wheeled quad was officially introduced—enthusiasts had been converting their trikes for some time—again primarily for farming, but its recreational appeal soon became apparent. At the same time a market for racing models was developing. Paul Anderson, a former British quad racing champion, says the quad’s recreational appeal lies in its potential to deliver a safe thrill. It’s a mix between a motorbike and driving a car; when you turn a corner, you’ve got to lean into the corner, and then if the ground’s greasy, the rear end slides out, he says. “Plus they’re much easier to ride than a two-wheeled motorcycle.“ The quad bike, in short, provides middle-aged excitement for men who think a Harley might be a bit dangerous. Anderson is keen to point out that quad bikes are, in his experience, much safer than motorcycles. “With quad racing it’s very rare that we see anybody having an accident and getting injured,“ he says. “In the right hands, personally, I think a quad bike is a very safe recreational vehicle“, he adds. Outside of racing, quad bikes are growing in popularity and injuries have trebled in the last five years. Although retailers offer would-be purchasers basic safety instructions and recommend that riders wear gloves, helmets, goggles, boots and elbow pads, there is no licence required to drive a quad bike and few ways to encourage people to ride them wisely. Employers are required to provide training to workers who use quad bikes, but there is nothing to stop other buyers hurting themselves. For the rest of the world, quad bikes are here to stay. They feature heavily in the programmes of holiday activity centres, they have all but replaced the tractor as the all-purpose agricultural workhorse and now police constables ride them while patrolling the Merseyside coastline. It has more or less usurped the beach buggy, the dirt bike and the snowmobile, anywhere they can go the quad bike can. They even race them on ice. You can’t drive round Lake Windermere on one, or at least nobody’s tried it yet. Just wait.

According to the passage, the scientists carried out their researches on______.

NNK is usually considered to be one of the direct causes of______.

What, according to the passage, makes the research conducted by the scientists at the Oregon Department of Health so unique?

As is used in paragraph 4, the phrase “a control group“ refers to______.

How many states in the United States have banned smoking in restaurants?