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单选题{{B}}TEXT B{{/B}} Researchers investigating brain size and mental ability say their work offers evidence that education protects the mind from the brain's physical deterioration. It is known that the brain shrinks as the body ages, but the effects on mental ability are different from person to person. Interestingly, in a study of elderly men and women, those who had more education actually had more brain shrinkage. "That may seem like bad news," said study author Dr. Edward Coffey, a professor of psychiatry and of neurology at Henry Ford Health System in Detroit. However, he explained, the finding suggests that education allows people to withstand more brain-tissue loss before their mental functioning begins to break down. The study, published in the July issue of Neurology, is the first to provide biological evidence to support a concept called the "reserve" hypothesis, according to the researchers. In recent years, investigators have developed the idea that people who are more educated have greater cognitive reserves to draw upon as the brain tissue to spare. Examining brain scans of 320 healthy men and women aged 66 to 90, researchers found that for each year of education the subjects had, there was greater shrinkage of the outer layer of the brain known as the cortex. Yet on tests of cognition and memory, all participants scored in the range indicating normal. "Everyone has some degree of brain shrinkage," Coffey said. "People lose (on average) 2.5 percent adecade starting at adulthood." There is, however, a "remarkable range" of shrinkage among people who show no signs of mental decline, Coffey noted. Overall health, lie said, accounts for some differences in brain size. Alcohol or drug use, as well as medical conditions such as diabetes and high blood pressure, contribute to brain-tissue loss throughout adulthood. In the absence of such medical conditions, Coffey said, education level helps explain the range of brain shrinkage exhibited among the mentally-fit elderly. The more-educated can withstand greater loss. Coffey and colleagues ganged shrinkage of the cortex by measuring the cerebrospinal fluid surrounding the brain. The greater the amount of fluid means the greater the cortical shrinkage. Controlling the health factors that contribute to brain injury, the researchers found that education was related to the severity of brain shrinkage. For each year of education from first grade on, subjects had an average of 1.77 milliliters more cerebrospinal fluid around the brain. For example, Coffey's team reported, among subjects of the same sex and similar age and skull size, those with 16 years of education had 8 percent to 10 percent more cerebrospinal fluid compared with those who had four years of schooling. Of course, achieving a particular education level is not the definitive measure of someone's mental capacity. And, said Coffey, education can be "a proxy for many things". More-educated people, he noted, are often less likely to have habits, such as smoking, which harm overall health. But Coffey said that his team's findings suggest that like the body, the brain benefits from exercise. "The question is whether by continuing to exercise the brain we can forestall the effects of (brain shrinkage) ," he said. "My hunch is that we can." According to Coffey, people should strive throughout life to keep their brains alert by exposing themselves to new experiences. Traveling is one way to stimulate the brain, he said; a less adventuresome way is to do crossword puzzles. "A hot topic down the road," Coffey said, "will be whether education even late in life has a protective effect against mental decline." Just how education might affect brain cells is unknown. In their report, the researchers speculated that in people with more education, certain brain structures deeper than the cortex may stay intact to compensate for cortical shrinkage.

单选题As a great poet, William Blake"s fame has been mainly resting upon two volumes of poems, Songs of Innocence and ______.

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单选题{{B}}TEXT B{{/B}} As every ancient mariner knew, traveling by sail is a simple way to go. Though the winds could be fickle and the boats pokey, the energy source that moved the ship was free, plentiful and renewable. Now tile same technology that conquered the oceans of Earth may conquer the ocean of space. This week a Russian and American consortium will announce plans for an April launch of the first so-called solar-sail vehicle, a multicasted spacecraft that will use sunlight to push itself along. To a public raised on smoke-and-fire rocketry, the idea of drawing energy straight from space seems fanciful. To the people behind the new ship, however, the technology is not only sensible but inevitable, the easiest way to reinvent the business of cosmic travel. "This allows us to use very little fuel to fly very great distances," says Bud Schurmeier, a former NASA engineer and an adviser to the project. "It' s an in- triguing concept." The idea behind solar sailing is simple. Although light is made of massless particles called photons, such ephemeral things exert real pressure, especially when they flow so close a source as the sun. Attach a sail of lightweight Mylar or other material to a spacecraft, set it up in the path of .that outrushing energy, and you ought to be able to move in almost any direction. NASA has a keen interest in solar sailing and had budgeted ＄ 5 million to invest igate 17 possible missions. It may select one as early as next month. But while the space agency has been mulling plans, the people behind the new ship, dubbed Cosmos I, have been getting set to fly. The project is the brainchild of Russia's Babakin Space Center, near Moscow, and the Planetary Society in Pasadena, Calif., a think tank founded in 1979 by astronomer Carl Sagan and others. The two groups had long been developing plans for a solar-sail mission but got the cash to make it happen only last year when Ann Druyan, Sagan's widow and head of the Media Company Cosmos Studios, and Joe Firmage, the founder of US Web, threw their names and about ＄ 4 million behind the effort. "I had talked to people about solar sailing before, "says Lou Friedman, former engineer at the Jet Propulsion Laboratory in Pasadena and director of the Planetary Society," but between the Russians' capabilities and Ann's vision, I knew this one would click." The spacecraft is a 3-ft. metal with eight 35-ft. metallic wings. Mylar petals sprout from it -- though the prototype used in the April launch will have just two petals. Mounted atop a reconfigured Russian ICBM and launched from a sub in the B arents Sea, the Cosmos I will fly to an altitude of 260 miles, where it will deploy the wings and float for a minute of so. If all goes well, the wings will then be jettisoned and the sphere aerobraked back to Earth, its bounce-down on Russian soil cushioned by air bags. By some measures, this cosmic lob shot is not that impressive, but for solar-sail scientists, the engineering is everything. Few doubt that when sunlight strikes the wings, the spacecraft will accelerate; the key is building wings that can open and pivot, allowing the ship to tack into the solar stream. If this mission works, a more ambitious orbital flight, using the eight-paneled craft, is set for the end of the year. The space-craft could circle Earth for months, surfing the sun until designers shut it down. "There will be a grandeur to it, "says Druyan, "a 70-ft. sail that will be visible to the whole planet." Grandeur aside, critics wonder if solar sails have a future. The technique is problematic in Earth orbit, since the changing position of sun relative to the space-craft makes constant tacking necessary. Sailing is best used for as the crow- flies shots to neighboring planets. Even in these cases, progress can be slow, since sunlight exerts, at most, 2 lbs. of pres- sure per square half-mile, requiring a year or more to rev a spacecraft to interplanetary speeds. Worse, beyond Jupiter, sunlight flickers out almost entirely; to go any farther would require energy beamen from Earth orbit, perhaps by giant laser howitzers. "None of these things has been tested, "says Mel Monte-merlo, one of NASA's solar-sailing chiefs. "We have a long way to go." Whether that will continue to seem such a long way may depend on the spring-time flight of Cosmos I. A successful mission has a way of making impossible technologies seem possible -- a big burden for a small rocket that will, for one day at least, carry the hopes of the world' s space community.

单选题HaierGroup'bidforMaytagis______.

单选题Yesterday, when Lil' Kim was sentenced to a year and a day in prison for lying to a grand jury, it seemed like more proof that rappers just can't stay out of jail. The conventional wisdom is that for hip-hop stars, there's a connection between crime and credibility. Every time some rapper poses for a mug shot, there is a chorus of commentators ready to declare that it's all a publicity stunt. The sentencing of Lil' Kim comes after two months when two rappers faced more serious charges. On June 17 the Philadelphia rapper Cassidy turned himself in to the police, who were looking for him as a suspect in a shooting that killed one man and wounded two others. Less than two weeks later, Cassidy's second album, "I'm a Hustla", arrived in stores; it makes its debut at No. 5 on this week's Billboard album chart. And in May, the emerging Atlanta rapper Gucci Mane surrendered in connection with the slaying of a rapper from Macon, Ga., named Pookie Loc; the arrest came the same day as the release of his new album, "Trap House" (Big Cat). Gucci Mane, who was jailed, has said that the killing was self-defense and has suggested that Pookie Loc was connected to his foe and former collaborator Young Jeezy, from the Atlanta group Boyzn' da Hood, which released its thrilling self-titled debut album on June 21; Jeezy's highly anticipated solo debut is due on July 26. It's clear that many rappers find themselves embroiled in violence, but it's also clear that Radric Davis had plenty to worry about even before he became a Southern sensation named Gucci Mane: he had previously been convicted on cocaine charges. And while a high-profile arrest certainly won't scare off hip-hop fans, it won't usually drive them to the record shops, either. Billboard said the arrest gave Gucci Mane a "big boost on the charts," but in fact his album made its debut at No. 101. That's not a very strong showing, especially considering the popularity of Gucci Mane's breakout hit, "Icy," a regional favorite that became a BET favorite, too. The strange truth is that being arrested or going to prison --even for murder --isn't likely to have much effect on a rapper's reputation. When Lil' Kim makes her inevitable return, she'll inevitably have some rhymes about her time inside. But although some fans might admire her for not testifying against her friends (in hip-hop, as elsewhere, loyalty counts for a lot), it is by no means clear that jail will help her career. For a rapper, having your name printed in the police blotter is likely merely to reinforce whatever perceptions fans already have.

单选题How many types of motors are generally used in the shaver?

单选题If the hypothesis stated at the end of the passage is true, it can be inferred that the crystalline proteins in the lenses of people with cataracts ______.

单选题British Prime Minister is appointed by A. the monarch. B. the House of Lords. C. the House of Common. D. the public.

单选题______ is the study of speech sounds in language or a language with reference to their distribution and patterning and to tacit rules governing pronunciation.A) PhonologyB) LexicographyC) LexicologyD) Morphology

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单选题WhichwordisnotusedbyNorberg-HodgetodescribetheLadakhipeople?

单选题The Witan (council or meeting of the wisemen) created by the Anglo-Saxons is the basis of the present British A. Parliament. B. Government. C. Monarchy. D. Privy Council.

单选题All of the following adjectives describe Annabel's impression of the landscape EXCEPT ______.

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单选题The semantic components of the word "man" can be expressed as ______.

单选题 {{B}}TEXT A{{/B}} To understand the marketing concept, it is only necessary to under stand the difference between marketing and selling. Not too many years ago, most industries concentrated primarily on the efficient production of goods, and then relied on "persuasive salesmanship" to move as much of these goods as possible. Such production and selling focuses on the needs. of the seller to produce goods and then convert them into money. Marketing, on the other hand, focuses on the wants of consumers'. It begins with first analyzing the preferences and demands of consumers and then producing goods that w/Il satisfy them. This eye-on-the-consumer approach is known as the marketing concept, which simply means that instead of trying to sell whatever is easiest to produce or buy for resale, the makers and dealers first endeavor to find out what the consumer wants to buy and then go about making it available for purchase. This concept does not imply that business is benevolent or that consumer satisfaction is given priority over profit in a company. There are al ways two sides to every business transaction-the firm and the customerand each must be satisfied before trade occurs. Successful merchants and producers, however, recognize that the surest route to profit is through understanding and catering to customers. A striking example of tile importance of catering to the consumer presented itself in mid-1985, when Coca Cola changed the flavor of its drink. Tile non-acceptance of the new flavor by a significant portion of the public brought about a prompt restoration of the Classic Coke, which was then marketed alongside the new. King Customer ruled!

单选题In writing, ______refers to series of words that begin with the same consonant or sound alike. A. alliteration B. anacoluthon C. anadiplosis D. anaphora