单选题It is a wise father that knows his own child, but today a man can boost his paternal (fatherly) wisdom—or at least confirm that he's the kid's dad. All he needs to do is to shell out $30 for paternity testing kit (PTK) at his local drugstore — and another $120 to get the results. More than 60000 people have purchased the PTKs since they first become available without prescriptions last year, according to Doug Fogg, chief operating officer of Identigene, which makes the over-the-counter(无需处方的) kits. More than two dozen companies sell DNA tests directly to the public, ranging in price from a few hundred dollars to more than $2500. Among the most popular: paternity and kinship(亲属关系) testing, which adopted children can use to find their biological relatives and families can use to track down kids put up for adoption. DNA testing is also the latest rage among passionate genealogists (系谱学者)— and supports businesses that offer to search for a family's geographic roots. Most tests require collecting cells by swabbing saliva(唾液) in the mouth and sending it to the company for testing. All tests require a potential candidate with whom to compare DNA. But some observers are skeptical. "There's a kind of false precision being hawked by people claiming they are doing ancestry testing," says Troy Duster, a New York University sociologist. He notes that each individual has many ancestors — numbering in the hundreds just a few centuries back. Yet most ancestry testing only considers a single lineage, either the Y chromosome(染色体) inherited through men in a father's line or mitochondrial(线粒体的) DNA, which is passed down only from mothers. This DNA can reveal genetic information about only one or two ancestors, even though, for example, just three generations back people also have six other great-grandparents or, four generations back, 14 other great-great-grandparents. Critics also argue that commercial genetic testing is only as good as the reference collections to which a sample is compared. Databases used by some companies don't rely on data collected systematically but rather lump together information from different research projects. This means that a DNA database may have a lot of data from some regions and not others, so a person's test results may differ depending on the company that processes the results. In addition, the computer programs a company uses to estimate relationships may be patented and not subject to peer review or outside evaluation.

单选题Speaker A: Oh, I am feeling dizzy now. You know I have just enjoyed much beer.Speaker B: Really? Don't you know it is a very important party? ______!

单选题She could make a teacher far superior ______ the average.

单选题The driver tried to prevent the accident by bringing the car to a sudden stop.

单选题Policeman: OK, buddy, your driving license. How fast were you going? William: Well, it was about 50 mph or less. I was driving very slowly. Policeman: 50 mph?______All right. That'll be one hundred dollars. A. Don' t you know the speed limit downtown is 40 mph? B. Don' t you know the controlled speed downtown is 40 mph? C. You need to fix your car. D. You drive in the wrong way.

单选题 Unless we spend money to spot and prevent asteroids (小行星) now, one might crash into Earth and destroy life as we know it, say some scientists. Asteroids are bigger versions of the meteoroids (流星)that race across the night sky. Most orbit the sun far from Earth and don't threaten us. But there are also thousands whose orbits put them on a collision course with Earth. Buy $ 40 million worth of new telescopes right now. Then spend $10 million a year for the next 25 years to locate most of the space rocks. By the time we spot a fatal one, the scientists say, we'll have a way to change its course. Some scientists favor pushing asteroids off course with nuclear weapons. But the cost wouldn't be cheap. Is it worth it? Two things experts consider when judging any risk are: 1) How likely the event is; and 2) How bad the consequences if the event occurs. Experts think an asteroid big enough to destroy lots of life might strike Earth once every 400,000 years. Sounds pretty rare-but if one did fall, it would be the end of the world. "If we don't take care of these big asteroids, they'll take care of us," says one scientist. "It's that simple." The cure, though, might be worse than the disease. Do we really want fleets of nuclear weapons sitting around on Earth? "The world has less to fear from doomsday (毁灭性的) rocks than from a great nuclear fleet set against them, "said a New York Times article.

单选题The brain drain of experts away from developing countries will greatly influence these coun tries' development of Usophisticated/U industry.

单选题 The rise of "temp" work has further magnified the decreasing fights and alienation of the worker. It is common corporate practice to phase out full-time employees and hire temporary workers to take on more workload in less time. When facing a pressing deadline, a corporation may pay $15～$ 20 per hour for a temp worker, but the temp worker will only see $ 7 or $ 8 of that money. The rest goes to temp agency, which is usually a corporate chain, such as Kelly Services, that blatantly makes its profits off other people's labor. This increases profits of the corporations because they can increase a workload, get rid of the employee when they're finished, and not worry about paying benefits or unemployment for that employee. I have had to work with temps a few times in my current position, and the workers only want one thing - a full-time job with benefits. We really wanted to hire one temp I was working with, but we could not offer her a full-time job because it would have been a breach in our contract with the temp agency that employed her. To hire a temp full-time, we would have had to pay the agency over a thousand dollars. Through this practice and policy, the temp agency locks its temporary workers into a horrible new form of servitude form which the worker cannot break free. Furthermore, corporate powers push workers to take on bigger workloads, work longer hours, and accept less benefits by instilling a paranoia in their workforce. The capitalist bosses assume dishonesty, disloyalty, and laziness amongst workers, and they breed a sense of guilt and fear through their assumptions. Where guilt doesn't seep in, bitterness, anger, and depression take over, the highest priorities of Big Business are to increase profits and limit liabilities. Personal relations and human needs are last on their list of priorities. So what we see is a huge mass of people who are alienated, disempowered, overworked, mentally and physically ill and who spend the vast majority of their time and energy on their basic survival. They are denied a chance to really "love", because they are forced to make profits for the capitalists in power.

单选题Nancy: Have you heard about Dana? She is going to get married with Graham. Scott: ______

单选题It amazes me that she's got the energy for all those parties.

单选题A: George, I would like to introduce a friend of mine, if I may: Albert Snow. Albert, this is George Smith. B: ______ A. How have you been? B. Pleased to meet you, George. C. Mind if I call you George? D. The pleasure is mine.

单选题I have an infatuation (迷恋) with autumn. The colors of the season, and the smells, have always thrilled me. I have always found joy in this time of year. The last few autumns of my life, however, I recollect in shades of gray rather than cheerful oranges and yellows. When I became a single mother, every aspect of life took on new meaning. Since I was used to carrying out most of the parental duties without much help during my marriage, I truly did not foresee how different parenting would become after the marriage was over. But suddenly I realized I was a statistic. The daily routine was not changed so much; it was the angle at which I had begun to look at life. I believed my ex-husband's lawyer was tracking every grade the children made, and I was under a microscope in this new town where the Children and I moved our "broken home." I feared having to eventually establish my family with each new teacher and each new term as a single-parent family. I just wanted to be us again, without the stigma (特征) of the label that put on us. During those few gray years, I would reassure myself that soon things would be better, and that I would someday be able to feel whole again. There is no mathematical equation of adults proportioned to children to equal a stable, loving family. Every family has its strengths. In fact, studies show that in families who read together, eat together and communicate openly, children are likely to succeed academically, as well as socially and emotionally. I am sure these habits are just as effective when practiced in single-parent families. I realize now that I am not a statistic. We are an active, vital family in this charming community, where we are not marked by any stigma of any statistics of any focus groups. We are given opportunity, all of us. We are surrounded by beauty and immersed in possibility. There is joy to be found here, in what we see around us and in creating our own rendition of how we want to be seen. There is strength and grace in our own willingness to break free from conformity without falling behind the barriers of self-imposed limitations or preconceived notions of where we should fit in this world according to research.

单选题What might driving on an automated highway be like? The answer depends on what kind of system is ultimately adopted. Two distinct types are on the drawing board. The first is a special-purpose lane system, in which certain lanes are reserved for automated vehicles. The second is a mixed traffic system： fully automated vehicles would share the road with partially automated or manually driven cars. A special-purpose lane system would require more extensive physical modifications to existing highways, but it promises the greatest gains in freeway (高速公路) capacity. Under either scheme, the driver would specify the desired destination, furnishing this information to a computer in the car at the beginning of the trip or perhaps just before reaching the automated highway. If a mixed traffic system was in place, automated driving could begin whenever the driver was on suitably equipped roads. If special-purpose lanes were available, the car could enter them and join existing traffic in two different ways. One method would use is a special onramp (人口引道). As the driver approached the point of entry for the highway, devices installed on the roadside would electronically check the vehicle to determine its destination and to ascertain that it had the proper automation equipment in good working order. Assuming it passed such tests, the driver would then be guided through a gate and toward an automated lane. In this case, the transition from manual to automated control would take place on the entrance ramp. An alternative technique could employ conventional lanes, which would be shared by automated and regular vehicles. The driver would steer onto the highway and move in normal fashion to a "transition" lane. The vehicle would then shift under computer control onto a lane reserved for automated traffic. (The limitation of these lanes to automated traffic would, presumably, be well respected, because all trespassers (非法进入者) could be swiftly identified by authorities. ) Either approach to joining, a lane of automated traffic would harmonize the movement of newly entering vehicles with those already traveling. Automatic control here should allow for smooth merging, without the usual uncertainties and potential for accidents. And once a vehicle had settled into automated travel, the drive would be free to release the wheel, open the morning paper or just relax. (392 words)

单选题The next decade could see commuters speeding to work at about 300 miles per hour aboard magnetic levitation vehicles, according to a report by Argonne National Laboratories. But before "maglev" vehicles can become commercial successes, the report says, people need to stop thinking of them as high-speed trains. Instead, consider them low-flying aircraft. Argonne contends that maglev vehicles will be best suited to replace commuter aircraft. Plane flights under 600 miles are the least energy-efficient, and maglev "planes" should cut these fuel needs by up to 75 percent. Reportedly, the money saved by a 2,000- mile maglev network linking major cities world more than pay for its construction in 20 years. The quiet purr of levitating crafts would also be a balm for neighborhoods tormented by the roar of conventional takeoffs and landings. The technology behind magnetic levitation is already well understood, the report notes. The west Germans and the Japanese already well understood, the report notes. The West Germans and the Japanese have several full-scale working models. Meanwhile, research in the United States has lapsed.

单选题We must ______ that the experiment is gong to be controlled as rigidly as possible.

单选题 The appeal of advertising to buying motives can have both negative and positive effects. Consumers may be convinced to buy a product of poor quality or high price because of an advertisement. For example, some advertisers have appealed to people's desire for better fuel economy for their cars by advertising automotive products that improve gasoline mileage. Some of the products work. Others are worthless and a waste of consumers' money. Sometimes advertising is intentionally misleading. A few years ago a brand of bread was offered to turned out that the bread was not dietetic (适合于节食的), but just regular bread. There were fewer calories because it was sliced very thin, but there were the same number of calories in every loaf. On the positive side, emotional appeals may respond to a consumer's real concerns. Consider fire insurance. Fire insurance maybe sold by appealing to fear of loss. But fear of loss is the real reason for fire insurance. The security of knowing that property is protected by insurance makes the purchase of fire insurance a worthwhile investment for most people. If consumers consider the quality of the insurance plans as well as the message in the ads, they will benefit from the advertising. Each consumer must evaluate her or his own situation. Are the benefits of the product important enough to justify buying it? Advertising is intended to appeal to consumers, but it does not force them to buy the product. Consumers still control the final buying decision.

单选题If the value-added tax was done away with, it would act as a ______ to consumption. A. progression B. prime C. stimulus D. stability

单选题Customer: I'm looking for a new living room set.Salesman: We have a lot of very nice sets. What style do you have in mind?Customer: ______.What I need is something comfortable.

单选题The touch excites no defensive response unless the approach is from above where the spider can see the motion, ______ on its hind legs, lifts its front legs, opens its fangs and holds this threatening posture as long as the object continues to move. A. in which case it rises B. in that case it rises C. in which case does it rise D. such being the case it rises

单选题Man: English is a difficult language to learn. Woman: ______