单选题In calculating the daily calorie requirement for an individual, variations in body size, physical activity and age should be______.

单选题The question of whether war is inevitable is one which has concerned many of the world's great writers. Before considering this question, it will be useful to introduce some related concepts. Conflict, defined as opposition among social entities directed against one another, is distinguished from competition, defined as opposition among social entities independently striving for something which is in inadequate supply. Competitors may not be aware of one another, while the parties to a conflict are. Conflict and competition are both categories of opposition, which has been defined as a process by which social entities function in the disservice, of one another. Opposition is thus contrasted with cooperation, the process by which social entities function in the service of one another. These definitions are necessary because it is important to emphasize that competition between individuals or groups is inevitable in a world of limited resources, but conflict is not conflict; nevertheless, is very likely to occur, and is probably ,an essential and desirable element of human societies. Many authors have argued for the inevitability of war from the premise that in the struggle for existence among animal species, only the fittest survive. In general, however, this struggle in nature is competition, not conflict. Social animals, such as monkeys and cattle, fight to win or maintain leadership of the group. The struggle for existence occurs not in such fights, but in the competition for limited feeding areas and for the occupancy of areas free from meat-eating animals. Those who fail in this competition starve to death or become victims to other species. This struggle for existence does not resemble human war, but rather the competition of individuals for jobs, markets, and materials. The essence of the struggle is the competition for the necessities of life that are insufficient to satisfy all. Among nations there is competition in developing resources, trades, skills, and a satisfactory way of life. The successful nations grow and prosper; the unsuccessful decline. While it is true that this competition may induce efforts to expand territory at the expense of others, and thus lead to conflict, it cannot be said that war-like conflict among nations is inevitable, although competition is.

单选题What can we learn about the result of the latest study?

单选题The word "pronounced" in the last sentence of the passage probably means ______.

单选题 waking Up from the American Dream There has been much talk recently about the phenomenon of "Wal-Martization" of America, which refers to the attempt of America"s giant Wal-Mart chain store company to keep its cost at rock-bottom levels. For years, many American companies have embraced Wal-Mart-like stratagems to control labor costs, such as hiring temps (temporary workers) and part-timers, fighting unions, dismantling internal career ladders and outsourcing to lower paying contractors at home and abroad. While these tactics have the admirable outcome of holding down consumer prices, they"re costly in other ways. More than a quarter of the labor force, about 34 million workers, is trapped in low-wage, often dead-end jobs. Many middle-income and highs killed employees face fewer opportunities, too, as companies shift work to subcontractors and temps agencies and move white-collar jobs to China and India. The result has been an erosion of one of America"s most cherished value: giving its people the ability to move up the economic ladder over their lifetimes. Historically, most Americans, even lows killed ones, were able to find poorly paid janitorial or factory jobs, then gradually climbed into the middle class as they gained experience and moved up the wage curve. But the number of workers progressing upward began to slip in 1970s. Upward mobility diminished even more in the 1980s as globalization and technology slammed blue-collar wages. Restoring American mobility is less a question of knowing what to do than of making it happen. Experts have decried schools" inadequacy for years, but fixing them is a long, arduous struggle. Similarly, there have been plenty of warnings about declining college access, but finding funds was difficult even in eras of large surpluses.

单选题Helicobacter pylori is one of humanity's oldest and closest companions, and yet it took scientists more than a century to recognize it. As early as 1875, German anatomists found spiral bacteria colonizing the mucus layer of the human stomach, but because the organisms could not be grown in a pure culture, the results were ignored and then forgotten. It was not until 1982 that Australian doctors Barry J. Marshall and J. Robin Warren isolated the bacteria, allowing investigations of H pylori's role in the stomach to begin in earnest. Over the next decade researchers discovered that people carrying the organisms had an increased risk of developing peptic ulcers--breaks in the lining of the stomach or duodenum--and that H pylori could also trigger the onset of the most common form of stomach cancer. Just as scientists were learning the importance of H pylori, however, they discovered that the bacteria are losing their foothold in the human digestive tract. Whereas nearly all adults in the developing would still carry the organism, its prevalence is much lower in developed countries such as the U.S. Epidemiologists believe that H pylori has been disappearing from developed nations for the past 100 years thanks to improved hygiene, which blocks the transmission of the bacteria, and to the widespread use of antibiotics. As H pylori has retreated, the rates of peptic ulcers and stomach cancer have dropped. But at the same time, diseases of the esophagus--including acid reflux disease and a particularly deadly type of esophageal cancer--have increased dramatically, and a wide body of evidence indicates that the rise of these illnesses is also related to the disappearance of H pylori.

单选题Teachers complain that children ______these tests without being able to write a decent essay, solve a multi-step math problem or construct a framework.

单选题The book, published ______, revived our interest in the author who had just died.

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单选题Comparisons were drawn between the development of television in the 20th century and the diffusion of printing in the 15th and 16th centuries. Yet much had happened (21) . As was discussed before, it was not (22) the 19th century that the newspaper became the dominant pre-electronic (23) , following in the wake of the pamphlet and the book and in the (24) of the periodical. It was during the same time that the communications revolution (25) up, beginning with transport, the railway, and leading (26) through the telegraph, the telephone, radio, and motion pictures (27) the 20th-century world of the motor car and the air plane. Not everyone sees that process in (28) . It is important to do so. It is generally recognized, (29) , that the introduction of the computer in the early 20th century, (30) by the invention of the integrated circuit during the 1960s, radically changed the process, (31) its impact on the media was not immediately (32) . As time were by, computers became smaller and more powerful, and they became "personal" too. as well as (33) , with display becoming sharper and storage (34) increasing. They were thought of, like people, (35) generations, with the distance between generations much smaller. It was within the computer age that the term "information society" began to be widely used to describe the context within which we now live.

单选题The editorial described drug abuse as the greatest {{U}}calamity{{/U}} of our age.

单选题The car ______ halfway for no reason. A. broke off B. broke down C. broke up D. broke our

单选题According to the first sentence of the article, you can conclude that______.

单选题The team leader of mountain climbers marked out ______.

单选题Many artists believe that successful imitation, far from being symptomatic of a lack of originality, is the step in learning to be ______. A. elegant B. confident C. creative D. imaginary

单选题The boy could not ______ the temptation of the piece of chocolate and revealed the secret.

单选题I was embarrassed when the______test paper my teacher spoke about turned out to be mine. I had forgotten to put my name on it.

单选题According to the passage, the greatest part of the solar energy that reaches the Earth is ______.

单选题{{B}}Text 4{{/B}} To sleep. Perchance to file? Findings published online this week by the Proceedings of the National Academy of Sciences further support the theory that the brain organizes and stows memories formed during the day while the rest of the body is catching zzz's. Gyorgy Buzsaki of Rutgers University and his colleagues analyzed the brain waves of sleeping rats and mice. Specifically, they examined the electrical activity emanating from the somatosensory neocortex (an area that processes sensory information) and the hippocampus, which is a center for learning and memory. The scientists found that oscillation in brain waves from the two regions appear to be intertwined. So-called sleep spindles (bursts of activity from the neocortex) were followed tens of milliseconds later by beats in the hippocampus known as ripples. The team posits that this interplay between the two brain regions is a key step in memory consolidation. A second study, also published online this week by the Proceedings of the National Academy of Sciences, links age-associated memory decline to high glucose levels. Previous research had shown that individuals with diabetes suffer from increased memory problems. In the new work, Antonio Convit of New York University School of Medicine and his collaborators studied 30 people whose average age was 69 to investigate whether sugar levels, which tend to increase with age, affect memory in healthy people as well. The scientists administered recall tests, brain scans and glucose tolerance tests, which measure how quickly sugar is absorbed from the blood by the body's tissues. Subjects with the poorest memory recollection, the team discovered, also displayed the poorest glucose tolerance. In addition, their brain scans showed more hippocampus shrinkage than those of subjects better able to absorb blood sugar. "Our study suggests that this impairment may contribute to the memory deficits that occur as people age." Convit says. "And it raises the intriguing possibility that improving glucose tolerance could reverse some age-associated problems in cognition." Exercise End weight control can help keep glucose levels in check, so there may be one more reason to go to the gym.