单选题In the tropical areas, ______.

单选题When enthusiasts talk of sustainable development, the eyes of most people glaze over. There is a whiff of sack-cloth and ashes about their arguments, which usually depend on people giving up the comforts of a modern economy to achieve some debatable greater good. Yet there is a serious point at issue. Modern industry pollutes, and it also seems to cause significant changes to the climate. What is needed is an industry that delivers the benefits without the costs. And the glimmerings of just such an industry can now be discerned. That industry is based on biotechnology. At the moment, biotech's main uses are in medicine and agriculture. But its biggest long-term impact may be industrial. Here, it will diminish demand for oil by taking the cheapest raw materials imaginable, carbon dioxide and water, and using them to make fuel and plastics. Plastics and fuels made in this way would have several advantages. They could accurately be called "renewables", since nothing is depleted to make them. They would be part of the natural carbon cycle, borrowing that element from the atmosphere for a few months, and returning it when they were burned or dumped. That means they could not possibly contribute to global warming. And they would be environmentally friendly in other ways. Bioplastics are biodegradable, since bacteria understand their chemistry and can therefore digest them. Biofuels, while not quite "zero emission" from the exhaust pipe (though a lot cleaner than petrol and diesel), would be cleaner overall even than the fuel-cell technology now being touted as an alternative to the internal-combustion engine. That is because making the hydrogen that fuel cells use is not an environmentally friendly process, and never will be—unless it, too, uses biotechnology. All this will, in the end, depend on costs. But these do not look unfavourable. Already, the price of bioplastics overlaps the top end of the petroleum-based plastics market. Bulk production should bring prices down, particularly when the raw materials are free. Meanwhile, ethanol would be a lot easier to introduce than fuel cells. Existing engines will run on it with minor tweaking, so there is no need to change the way cars are made. And since, unlike hydrogen, it is a liquid, the fuel-distribution infrastructure would not need radical change. The future could be green in ways that traditional environmentalists had not expected. Whether they will embrace that possibility, or stick to sack-cloth, remains to be seen.

单选题What does the author believe according to the passage?______

单选题Current Group, a Germantown-based technology firm, has taken over an ordinary looking house in Bethesda and turned it into a laboratory for smart-grid technology, the system the company believes will bring the nation's electricity grids into the digital age. In the front yard stands a utility pole hooked up to a special transformer that connects the power lines to high-speed Internet. Hundreds of sensors attached to the lines monitor how power flows through the home. That information is then sent back to the utility company. The process lets a utility more efficiently manage the distribution of electricity by allowing two-way communication between consumers and energy suppliers via the broadband network on the power lines. Based on data they receive from hundreds of homes, utilities can monitor usage and adjust output and pricing response to demand. Consumers can be rewarded with reduced rates by cutting back on consumption during peak periods. And computerized substations can talk to each other so overloaded circuits hand off electricity to those that axe not fully loaded, helping to prevent blackouts. Some utility companies have launched initiatives to give consumers data about their energy consumption habits in an effort to lower energy bills. Smart-grid technology takes such programs further by automating electricity distribution, which would make grids more reliable and efficient. By partnering with utilities, the company hopes to tap into $4.5 billion in stimulus grants intended to encourage smart-grid development. When he announced the funding, President Obama pointed to a project in Boulder, Colo., as an example of a successful smart-grid experiment. Current is one of the companies working on the project. Current's chief executive Tom Casey believes the technology will help utility companies better distribute electricity produced by renewable resources, such as solar panels or wind farms. "A smart grid's system can be paired up with the renewable resources so that when the renewable source is varying, the overall load can be varied as well," Casey told the House Select Committee on Energy Independence and Global Warming. "This will reduce or eliminate the need for backup coal or gas based power generation plants./

单选题What can be inferred from the passage about the agricultural sector of the economy after the Civil War?______

单选题It may not have generated much interest outside energy and investment circles, but a recent comment by Tidewater, Inc. president Dean Taylor sent earthquakes through the New Orleans business community. In June, Taylor told the Houston Chronicle that the international marine services company—the world's largest operator of ships serving the offshore oil industry—was seriously considering moving its headquarters, along with scores of administrative jobs, from the Crescent City to Houston, "We have a lot of sympathy for the city, " Taylor said. "But our shareholders don't pay us to have sympathy. They pay us to have resuits for them." It was the last thing the hurricane-scarred city needed to hear. Tidewater was founded here a little more than 50 years ago, and kept its main office in New Orleans throughout the oil bust of the-1980s and the following decades of industry consolidation, when dozens of energy firms all but abandoned New Orleans for greener pastures on the Texas coast. In the nearly two years since Hurricane Katrina ravaged the city, the pace of exodus has accelerated, complicating New Orleans' halting recovery; according to the local business weekly CityBusiness, the metropolitan area has lost 12 of the 23 publicly traded companies headquartered here, taking white-collar jobs, Corporate community support and sorely needed taxpayers with them—and threatening to leave the city even more dependent on a tourismbased economy than it was before the storm. Making matters worse, some observers say, is the city leadership's apparent indifference to the bloodletting. Just weeks after Hurricane Katrina in August 2005, Mayor Ray Nagin, then in the very early stages of a heated reelection bid, dismissed warnings that many companies, like displaced residents, might opt to relocate. Nagin said he hoped they would stay. "But if they don't," he said with typical glibness, "I'll send them a postcard. "The comment might have been written off as one of Nagin's many verbal missteps. But in the months that followed, the warnings turned out in many cases to be true, even as the city's rebuilding effort languished, infrastructure repairs limped along, the state reimbursement program for damaged homes faltered and the New Orleans' infamous crime rate made a sickening comeback. New Orleans "wasn't considered a great city for doing business before the storm. People were always dribbling out," says Peter Ricchiuti, a professor of economics at Tulane University. While many of the companies that made it through the storm could stand to benefit from the city's recovery, he says, Katrina may have hastened the loss of high-paying energy jobs. "We're losing the white-collar jobs and keeping the blue-collar jobs," he says. "We're becoming much more of a blue-collar oil industry." One of the latest examples is Chevron Corp. , which is building new offices in the northern suburbs, 40 miles north of the city across Lake Pontchartraln, and plans to transfer 550 employees from New Orleans to Covington by the end of the year. That would take well-paid people out of downtown New Orleans, a move that will impact the central business district's economy. "We made the decision in May, 2006, when our employees were making important housing decisions," says Qi Wilson, a Chevron spokesperson. The company; like many employees, decided the north shore offered better security should another hurricane strike, along with fewer of the post-Katrina headaches that still plague the city. The move "will make it easier to retain the talent we have, and to attract new talent," Wilson says.

单选题Energy will be one of the defining issues of this century. One thing is clear: the era of (1) oil is over. What we all do next will determine how well we meet the energy needs of the entire world in this century and (2) . Demand is soaring like (3) before. As populations grow and economies (4) , millions in the developing world are enjoying the benefits of a lifestyle that (5) increasing amounts of energy. In fact, some say that in 20 years the world will (6) 40% more oil than it does today. At the same time, many of the world's oil and gas fields are (7) . And new energy discoveries are mainly occurring in places where resources are difficult to (8) , physically, economically and even politically. When growing demand meets (9) supplies, the result is more (10) for the same resources. We can wait until a crisis forces us to do something. (11) we can (12) to working together, and start by asking the (13) questions.- How do we meet the energy needs of the developing world and those of industrialized nations? What role will renewables and (14) energies play? What is the best way to protect our environment? How do we accelerate our conservation efforts? (15) actions we take, we must look not just to next year, (16) to the next 50 years. At Chevron, we believe that innovation, collaboration and conservation are the (17) on which to build this new world. We cannot do this alone. Corporations, governments and every citizen of this planet must be part of the solution as (18) as they are part of the problem. We (19) scientists and educators, politicians and policy-makers, environmentalists, leaders of industry and each one of you to be part of (20) the next era of energy.

单选题If you leave a loaded weapon lying around, it is bound to go off sooner or later. Snow-covered northern Europe heard the gunshot loud and clear when Russia cut supplies to Ukraine this week as part of a row about money and power, the two eternal battlegrounds of global energy. From central Europe right across to France on the Atlantic seaboard, gas supplies fell by more than one-third. For years Europeans had been telling themselves that a cold-war enemy which had supplied them without fail could still be depended on now it was an ally ( of sorts). Suddenly, nobody was quite so sure. Fearing the threat to its reputation as a supplier, Russia rapidly restored the gas and settled its differences with Ukraine. But it was an uncomfortable glimpse of the dangers for a continent that imports roughly half its gas and that Gérard Mestrallet, boss of Suez, a French water and power company, expects to be importing 80% of its gas by 2030--much of it from Russia. It was scarcely more welcome for America, which condemned Russia"s tactics. And no wonder: it consumes one-quarter of the world"s oil, but produces only 3% of the stuff. Over the coming years, the world"s dependence on oil looks likely to concentrate on the Middle East, particularly Saudi Arabia. Russian oil had seemed a useful alternative. Fear of the energy weapon has a long history. When producers had the upper hand in the oil embargo of 1973-74, Arab members of the Organisation of the Petroleum Exporting Countries (OPEC) cut supply, sowing turmoil and a global recession. When consumers had the upper hand in the early 1990s, the embargo cut the other way. After Saddam Hussein invaded Kuwait in 1990, the world shut in 5m barrels a day (b/d) of production from the two countries in an attempt to force him out. With oil costing $ 60 a barrel, five times more than the nominal price in 1999, and spot prices for natural gas in some European and American markets at or near record levels, power has swung back to the producers for the first time since the early 1980s. Nobody knows how long today"s tight markets will last. "It took us a long time to get there and it will take us a long time to get back," says Robin West, chairman of PFC Energy in Washington. A clutch of alarmist books with titles such as "The Death of Oil" predict that so little oil is left in the ground that producers will always have pricing power. The question is how worried consumers should be. What are the threats to energy security and what should the world do about them? The answers suggest a need for planning and a certain amount of grim realism, but not for outright panic.

单选题What"s your earliest childhood memory? Can you remember learning to walk? Or talk? The first time you heard thunder or watched a television program? Adults seldom 1 events much earlier than the year or so before entering school, 2 children younger than three or four 3 retain any specific, personal experiences. A variety ofexplanations have been 4 by psychologists for this "childhood amnesia", One argues that the luppocampus, the region ofthe brain which is 5 for forming memories, does not mature until about the age of two. But the most popular theory 6 that, since adults don"t think like children, they cannot 7 childhood memories. Adults thinkin words, and their life memories are like stories or 8 —one event follows another as in a novel or film. 9 , when they search through their mental 10 for early childhood memories to add to this verbal life story, they don"t find any that fit the 11 . It"s like trying to find a Chinese word in an English dictionary. Now psychologist Annette Simms of the New York State University offers a new 12 for childhood amnesia. She argues that there simply aren"t any early childhood memories to recall. According to Dr. Simms, children need to learn to use someone else"s spoken 13 oftheir personal 14 in order to turn their own short-term, quickly forgotten 15 of them into long-term memories. 16 , children have to talk about their 17 and hear others talk about them—Mother talking about the afternoon 18 looking for seashells at the beach or Dad asking them about their day at Ocean Park. Without this 19 reinforcement, says Dr. Simms, children cannot form 20 memories oftheir personal experiences.

单选题Some countries are more populous; some have more crime. But in no other country are crime fighters quite so knowledgeable about citizens as in Britain. On January 4th a boastful Home Office detailed the triumphs of the world's biggest forensic DNA database, which holds samples from more than 5% of the entire population of England and Wales. Recent changes to the rules governing the database mean that it may eventually hold profiles from more than a fifth of all adults. Once a country starts storing DNA samples from criminals it is hard to resist the urge to expand the collection. When the National DNA Database (NDNAD) was set up, in 1995, samples could only be taken from those charged with "recordable" offences. If a suspect was not tried, or was freed, the sample had to be destroyed and the profile removed from the database. That law was abandoned in 2001, after two men who had been convicted of murder and rape had their cases overturned on appeal--the DNA evidence against them related to crimes they had not beep convicted of, and so ought to have been removed from the database. The change has led to the retention of around 200,000 samples that world previously have been destroyed. Some 7,591 of these were subsequently matched with samples from crime scenes, including those from 88 murders and 116 rapes. And since April 2004, police have been able to take and keep samples from anyone arrested for a recordable offence, even if charges do not ensue. The main reason the NDNAD is larger than databases in other countries is that Britain was first to start using DNA as an investigative tool. So not only has it had time to collect more DNA samples, but it has also had longer to appreciate the sheer power of a large database.." Every other country that does databasing will get to where Britain is now," says Chris Asplen, a consultant to law enforcement agencies and governments on DNA technology. The increased use of DNA evidence has given rise to intriguing new courtroom defences. DNA tests are now so sensitive that they can detect if a person has sneezed or sweated near an object. John Swain, a barrister with a background in biochemistry, recently defended a man charged with armed robbery. The defendant's DNA was on the gun that was used, but the defence argued that he might just have been near it after he had been to the gym, and that an errant bead of sweat could account for the presence of his DNA on a weapon he had never handled. He was declared not guilty.

单选题According to the author, research on palliative care for cancer______.