单选题Car Thieves Could Be Stopped Remotely Speeding off in a stolen car, the thief thinks he has got a great catch. But he is in a nasty surprise. The car is fitted with a remote immobilizer, and a radio signal from a control center miles away will ensure that once the thief switches the engine 1 , he will not be able to start it again. For now, such devices 2 only available for fleets of trucks and specialist vehicles used on construction sites. But remote immobilization technology could soon start to trickle down to ordinary cars, and 3 be available to ordinary cars in the UK 4 two months. The idea goes like this. A control box fitted to the car incorporates 5 miniature cellphone, a microprocessor and memory, and a GPS satellite positioning receiver. 6 the car is stolen, a coded cellphone signal will tell the unit to block the vehicle"s engine management system and prevent the engine 7 restarted. There are even plans for immobilizers 8 shut down vehicles on the move, though there are fears over the safety implications of such a system. In the UK, an array of technical fixes is already making 9 harder for car thieves. "The pattern of vehicles crime has changed," says Martyn Randall of Thatcham, a security research organization based in Berkshire that is funded in part 10 the motor insurance industry. He says it would only take him a few minutes to 11 a novice how to steal a car, using a bare minimum of tools. But only if the car is more than 10 years old. Modem cars are a far tougher proposition, as their engine management computer will not 12 them to start unless they receive a unique ID code beamed out by the ignition key. In the UK, technologies like this 13 achieve a 31 percent drop in vehicle-related crime since 1997. But determined criminals are still managing to find other ways to steal cars. Often by getting hold of the owner"s keys in a burglary. In 2000, 12 percent of vehicles stolen in the UK were taken by using the owner"s keys, which doubles the previous year"s figure. Remote-controlled immobilization system would 14 a major new obstacle in the criminal"s way by making such thefts pointless. A group that includes Thatcham, the police, insurance companies and security technology firms have developed standards for a system that could go on the market sooner than the 15 expects.

单选题The starving children were a {{U}}pathetic{{/U}} sight.

单选题A New Strategy to Overcome Breast Cancer Post-menopausal (绝经后的) women who walk for an hour a day can cut their chance of breast cancer significantly, a study has suggested. The report, which followed 73,000 women for 17 years, found walking for at least seven hours a week lowered the risk of the disease. The American Cancer Society team said this was the first time reduced risk was specifically linked to walking. UK experts said there was more evidence that lifestyle influenced cancer risk. A recent poll for the charity Ramblers found a quarter of adults walk for no more than an hour a week, but being active is known to reduce the risk of a number of cancers. This study, published in Cancer Epidemiology, Biomarkers & Prevention, followed 73,615 women out of 97,785 aged 50 -74 who had been recruited by the American Cancer Society between 1992 and 1993, so it could monitor the incidence of cancer in the group. They were asked to complete questionnaires on their health and on how much time they were active and participating in activities such as walking, swimming and aerobics (有氧运动) and how much time they spent sitting watching television or reading. They completed the same questionnaires at two-year intervals between 1997 and 2009. Of the women, 47% said walking was their only recreational activity. Those who walked for at least seven hours per week had a 14% lower risk of breast cancer compared to those who walked three or fewer hours per week. Dr. Alpa Patel, a senior epidemiologist at the American Cancer Society in Atlanta, Georgia, who led the study, said: "Given that more than 60% of women report some daily walking, promoting walking as a healthy leisure-time activity could be an effective strategy for increasing physical activity amongst post-menopausal women. We were pleased to find that without any other recreational activity, just walking one hour a day was associated with a lower risk of breast cancer in these women." "More strenuous (紧张的) and longer activities lowered the risk even more." Baroness Delyth Morgan, chief executive of Breast Cancer Campaign, said: "This study adds further evidence that our lifestyle choices can play a part in influencing the risk of breast cancer and even small changes incorporated into our normal day-to-day activity can make a difference." She added: "We know that the best weapon to overcoming breast cancer is the ability to stop it occurring in the first place. The challenge now is how we turn these findings into action and identify other sustainable lifestyle changes that will help us prevent breast cancer."

单选题Archaeologists (考古学家) have discovered remains of million-year-old animals in excavations.

单选题You should have blended the butter with the sugar thoroughly A. spread B. mixed C. beaten D. covered

单选题The best title for the passage is _______.

单选题Numerous attempts have been made to hide the truth.A. ManyB. SuccessfulC. EffectiveD. Unsuccessful

单选题What happened when honey badgers got used to humans around them?

单选题Free Statins With Fast Food Could Neutralize Heart Risk Fast food outlets could provide statin drugs free of 1 so that customers can reduce the heart disease dangers of fatty food, researchers at Imperial College London 2 in a new study. Statins reduce the 3 of unhealthy "LDL" cholesterol in the blood. A wealth of trial data has proven them to be highly effective at 4 a person"s heart attack risk. In a paper published in the American Journal of Cardiology , Dr. Darrel Francis and colleagues calculate that the reduction in heart attack risk offered by a statin is 5 to offset the increase in heart attack risk from 6 a cheeseburger and drinking a milkshake. Dr. Francis, from the National Heart and Lung Institute at Imperial College London, who is the senior author of the study, said, "Statins don"t cut out all of the 7 effects of cheeseburgers and French fries. It"s better to avoid fatty food altogether. But we"ve worked out that in terms of your 8 of having a heart attack, taking a statin can reduce your risk to more or less the same 9 as a fast food meal increases it." "It"s ironic that people are free to take as many unhealthy condiments in fast food outlets as they 10 , but statins, which are beneficial to heart health, have to be prescribed. It 11 sense to make risk-reducing stains available just as easily as the unhealthy condiments that are provided free of charge. It would cost less than 5 pence per 12 —not much different to a sachet of sugar," Dr. Francis said. When people engage in risky behaviours like driving or smoking, they"re encouraged to take 13 that lower their risk, like 14 a seatbelt or choosing cigarettes with filters. Taking a statin is a rational way of 15 some of the risks of eating a fatty meal.

单选题The doctors have abandoned the hope to rescue the old man.

单选题Trying to Find a Partner One of the most striking findings of a recent poll in the UK is that of the people interviewed, one in two believes that it is becoming more difficult to meet someone to start a family with. Why are many finding it increasingly difficult to start and sustain intimate relationships? Does modern life really make it harder to fall in love? Or are we making it harder for ourselves? It is certainly the case today that contemporary couples benefit in different ways from relationships. Women no longer rely upon partners for economic security or status. A man doesn't expect his spouse to be in sole charge of running his household and raising his children. But perhaps the knowledge that we can live perfectly well without a partnership means that it takes much more to persuade people to abandon their independence. In theory, finding a partner should be much simpler these days. Only a few generations ago, your choice of soulmate (心上人) was constrained by geography, social convention and family tradition. Although it was never explicit, many marriages were essentially arranged. Now those barriers have been broken down. You can approach a builder or a brain surgeon in any bar in any city on any given evening. When the world is your oyster (牡蛎), you surely have a better chance of finding a pearl. But it seems that the old conventions have been replaced by an even tighter constraint: the tyranny of choice. The expectations of partners are inflated to an unmanageable degree: good looks, impressive salary, kind to grandmother and right socks. There is no room for error in the first impression. We think that a relationship can be perfect. If it isn't, it is disposable. We work to protect ourselves against future heartache and don't put in the hard emotional labor needed to build a strong relationship. Of course, this is complicated by realities. The cost of housing and child-rearing creates pressure to have a stable income and career before a life partnership.

单选题The sea turtle's natural habitat has been considerably reduced.A. suddenlyB. generallyC. slightlyD. greatly

单选题Radiocarbon Dating Nowadays scientists can answer many questions about the past through a technique called radiocarbon (放射), or carbon-14, dating. One key to understanding how and why something happened is to discover when it happened. Radiocarbon dating was developed in the late 1940s by physicist Willard F. Libby at the University of Chicago. An atom of ordinary carbon, called carbon-12, has six protons (质子) and six neutrons (中子) in its nucleus(原子核). Carbon-14,or C-14,is a radioactive,unstable form of carbon that has two extra neutrons. It returns to a more stable form of carbon through a process called decay(衰减). This process involves the loss of the extra neutrons and energy from the nucleus. In Libby's radiocarbon dating technique, the weak radioactive emissions (放射)from this decay process are counted by instruments such as a radiation detector and counter. The decay rate is used to determine the proportion of C-14 atoms in the 'sample being dated. Carbon-14 is produced in the Earth's atmosphere when nitrogen(氮)-14,or N-14,interacts with cosmie rays(宇宙射线). Scientists believe since the Earth was formed, the amount of nitrogen in the atmosphere has remained constant. Consequently,C-14 formation is thought to occur at a constant rate. Now the ratio of C-14 to other carbon atoms in the atmosphere is known. Most scientists agree that this ratio is useful for dating items back to at least 50,000 years. All life on Earth is made of organic molecules(分子)that contain carbon atoms coming from the atraosphere. So all living things have about the same ratio of C-14 atoms to other carbon atoms in their tissues(组织). Once an organism(有机体)dies it stops taking in carbon in any form, and the C-14 already ,resent begins to decay. Over time the amount of C-14 in the material decreases, and the ratio of C-14 to other carbon atoms goes down. In terms of radiocarbon dating,the fewer C-14 atoms in a sample,the older that sample is.

单选题阅读下面的短文，文中有15处空白，没处空白给出了4个选项，请根据短文的内容从4个选项中选择1个最佳答案。 Man and Computer What makes people different from computer programs? What is the missing element that our theories don't yet{{U}} (51) {{/U}}．for? The answer is simple: People read newspaper stories {{U}}(52) {{/U}}．a reason to learn more about what they are interested in. Computers, on the other hand, don't. In fact, computers don't{{U}} (53) {{/U}}． have interests; there is nothing in particular that they are trying to find out when they read. If a computer{{U}} (54) {{/U}}． is to be amodelof story understanding, it should also read for a "purpose". Of course, people have several goals that do not make{{U}} (55) {{/U}}to attribute to computers. One might read a restaurant guide in order to satisfy hunger or entertainment goals, or to {{U}}(56) {{/U}}a good place to go for a business lunch. Computers do not{{U}} (57) {{/U}}, and computers do not have business lunches. However, these physiological and social goals give{{U}} (58) {{/U}}to several intellectual or cognitive(认识的) goals. A goal to satisfy hunger gives rise to goals to find{{U}} (59) {{/U}}about the name of a restaurant which serves the desired type of food, how expensive the restaurant is, the {{U}}(60) {{/U}}of the restaurant, etc. These are goals to{{U}} (61) {{/U}}information or knowledge, what we are calling{{U}} (62) {{/U}}goals. These goals can be held by computers too a computer might "want" to find out the location of a restaurant, and read a guide in order to do so{{U}} (63) {{/U}}the same way as a person might. While such a goal would not{{U}} (64) {{/U}}out of hunger in the case of the computer, it might{{U}} (65) {{/U}}rise out of the "goal" to learn more about restaurants.

单选题Ford"s Assembly Line When it comes to singling out those who have made a difference in all our lives, you cannot overlook Henry Ford. A historian a century from now might well conclude that it was Ford who most influenced all manufacturing, everywhere, even to this day, by introducing a new way to make cars—one, strange to say, that originated in slaughterhouses (屠宰场). Back in the early 1900s, slaughterhouses used what could have been called a "disassembly line". Ford reversed this process to see if it would speed up production of a part of an automobile engine called a magneto (磁力发动机). Rather than have each worker completely assemble a magneto, one of its elements was placed on a conveyer, and each worker, as it passed, added another component to it, the same one each time. Professor David Hounshell of the University of Delaware, an expert on industrial development, tells what happened. "The previous day, workers carrying out the entire process averaged one assembly every 20 minutes. But on that day, on the line, the assembly team averaged one every 13 minutes and 10 seconds per person." Within a year, the time had been reduced to five minutes. In 1913, Ford went all the way. Hooked together by ropes, partially assembled vehicles were towed (拖，拉) past workers who completed them one piece at a time. It wasn"t long before Ford was turning out several hundred thousand cars a year, a remarkable achievement then. And so efficient and economical was this new system that he cut the price of his cars in half, to $260, putting them within reach of all those who, up until that time, could not afford them. Soon, auto makers all over the world copied him. In fact, he encouraged them to do so by writing a book about all of his innovations, entitled Today and Tomorrow . The Age of the Automobile had arrived. Today, aided by robots and other forms of automation, everything from toasters to perfumes is made on assembly lines.

单选题 Egypt Felled by Famine Even ancient Egypt' mighty pyramid builders were powerless in the face of the famine that helped bring down their civilian around 2180 BC. Now evidence gleaned(搜集) from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame—and the same or worse could happen today. The ancient Egyptians depended on the Niles annual floods to irrigate their crops. But any change in climate that pushed the African monsoons(季风)southwards out of Ethiopia would have diminished these floods. Dwindling(逐渐变少)rains in the Ethiopian highlands would have meant fewer plants to establish the soil. When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment(沉积物)from the White Nile. The Blue Nile mud has a different isotope signature(特征) from that of the White Nile. So by analyzing isotope(同位素；核素) differences in mud deposited in the Nile Delta, Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river. Krom reasons that during periods of drought, the amount of the Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4,500 to 4,200 years ago, immediately predates the fall of the Egypt's old Kingdom. The weakened waters would have been catastrophic for the Egyptians. Changes that affect food supply don't have to be very large to have a ripple effect in societies, says Bill Ryan of the Lamont Doherty Earth Observatory(天文台) in New York. Similar events today could be even more devastating, says team member Daniel Stanley, a geoarchaeologist(地质考古学家) from the Smithsonian Institution in Washington, D. C. "Anything humans do to shift the climate belts would have an even worse effect along the Nile system because the populations have increased dramatically."

单选题He decided to quit smoking because of his cough.A. give upB. put upC. set upD. take up

单选题In fine days, you"d better open windows to ventilate the room.

单选题What leads to the formation of a black hole?

单选题The population of the island Uconsists/U of equal numbers of men and women.