题目内容
WWW is popular for its multimedia transmission and friendly (71) . Although the speed of network has been improved considerably in recent years, the rapid (72) of using the Internet, the inherited character of delay in the network and the Request/Response working mode of WWW still make the Internet traffic very (73) and give no guarantee on the Quality of Service. Because HTTP has no states, the web server cannot know the users’ demand and the users’ requests cannot be predicted Taking advantage of a cache mechanism and the time locality of WWW accesses, the browser can preserve the documents ever accessed in the local machine. By this means, for the documents in the local cache, the browser does not need to send the requests to the remote server or to receive the whole responses from the remote one Pre-fetching uses the space locality of accesses First, the users’ access requests are predicted according to the users’ current request. Secondly, the expected pages are fetched into the local cache when the user is brow sing the current page. Finally, the users can access these pages downloaded from the local cache. And this can reduce the access delay to some degrees. Pre-fetching is one kind of active caches that can cache the pages which are still not requested by the user. The application of pre-fetching technology in the web can greatly reduce the waiting time after users have sent their requests. This paper brings forward an intelligent technique of web pre-fetching, which can speed up fetching web pages. In this technique, we use a simplified WWW data model to represent the data in the cache of web browser to mine the association rules. We store these rules in a knowledge base so as to (74) the user’s actions. In the client sides, the agents are responsible for mining the users’ interest and pre-fetching the web pages, which are based on the interest association repository. Therefore it is (75) for the users to speed up the browsing. （74）处填（）。
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Chocolate to Live For! A study published in the Journal of the American Medical Association in 2003 reported that dark chocolate may lower your blood pressure. Researchers at the University of Cologne studied men and women who were recently diagnosed with mild high blood pressure. Half were given 100g (fabout 3.5 ounces) of dark chocolate per day and half were given white chocolate. After only two weeks systolic (收缩的) blood pressure decreased on average by five points and diastolic (以及舒张的) blood pressure by two points in those consuming dark chocolate, but not those consuming white chocolate. In a similar study, researchers from Italy reported in the American Heart Association journal Hypertension that 3.5 ounces of dark chocolate for one week lowered systolic blood pressure by 12 points and diastolic blood pressure by 8.5 points when blood pressure was monitored continuously for 24 hours. Insulin (胰岛素) sensitivity and LDL cholesterol also improved. No benefits were seen with white chocolate. Another study published in the Journal of the American College of Cardiology found that chocolate may help repair damage to smokers’ blood vessels, at least temporarily. why Chocolate increases your body’ s production of nitric oxide (一氧化氮), a powerful substance that causes your blood vessels to relax and dilate. This, in turn, causes an increase in blood flow and a decrease in blood pressure--like opening a water spigot (水龙头). A study published in July in the Journal of the American Medical Association reported that just 30 calories per day of dark chocolate lowered blood pressure and increased nitric oxide production after 18 weeks. Nitric oxide is also stimulated by drugs such as Viagra and Levitra, which increase blood flow to the penis and enhance erections. This may be one of the reasons why chocolate has had a long reputation as an aphrodisiac (壮阳药). Casanova (卡萨诺瓦) is said to have considered it as his "favorite breakfast dish. " Chocolate also contains phenylethylamine (苯乙胺), which research suggests is a stimulant that is released when you’ re interacting with someone intimately. Which of the following is not a benefit of dark chocolate according to all the studies
3.Born to be Big In 2006 scientists at the Harvard School of Public Health reported that the prevalence of obesity (肥胖) in infants under 6 months had risen 73 percent since 1980. "This epidemic of obese 6 - month - olds," as Robert Lustig of the University of California, San Francisco, calls it, poses a problem for conventional explanations of the fattening of America. "Since they’ re eating only formula (配方奶) or breast milk, and never exactly got a lot of exercise, the obvious explanations for obesity don’t work for babies," he points out. "You have to look beyond the obvious. " The search for the non - obvious has led to an early - life exposure to Paces of chemicals in the environment. Evidence has been steadily accumulating that certain hormone - mimicking pollutants (污染物质), ubiquitous (到处存在的) in the food chain, have two previously effects. They act on genes in the developing fetus (胎儿) and newborn to turn more precursor (前体) cells into fat cells, which stay with you for life. And they may alter metabolic (新陈代谢的) rate, so that the body saves calories rather than burning them. "The evidence now emerging says that being overweight is not just the result of personal choices about what you eat, combined with inactivity," says Retha Newbold of the National Institute of Environmental Health Sciences (NIEHS). " Exposure to environmental chemicals during development may he contributing to the obesity epidemic. "They are not the cause of extra pounds in every person who is overweight but environmental chemicals may well account for a good part of the current epidemic, especially in those under 50. The new thinking about obesity comes at a critical time politically. As the debate over health care shines a light on the country’s unsustainable spending on doctors, hospitals, and drugs, the obese make tempting scapegoats (替罪羊). About 60 percent of Americans are overweight or obese, and their health - care costs are higher: $3,400 in annual spending for a normal- weight adult versus $ 4,870 for an obese adult, mostly due to their higher levels of type 2 diabetes, heart disease, and other conditions. If those outsize costs inspire greater efforts to prevent and treat obesity, fine. But if they lead to demonizing (妖魔化) the obese - caricaturing (画成漫画讽刺) them as lazy pigs raising insurance premiums (保险费) for the rest of us -that’ s a problem, and not only for ethical reasons: it threatens to obscure (使不明显) that one potent cause of weight gain may be largely beyond an individual’s control. There are already many cartoons depicting the obese as lazy pigs raising insurance premiums.
3.Born to be Big In 2006 scientists at the Harvard School of Public Health reported that the prevalence of obesity (肥胖) in infants under 6 months had risen 73 percent since 1980. "This epidemic of obese 6 - month - olds," as Robert Lustig of the University of California, San Francisco, calls it, poses a problem for conventional explanations of the fattening of America. "Since they’ re eating only formula (配方奶) or breast milk, and never exactly got a lot of exercise, the obvious explanations for obesity don’t work for babies," he points out. "You have to look beyond the obvious. " The search for the non - obvious has led to an early - life exposure to Paces of chemicals in the environment. Evidence has been steadily accumulating that certain hormone - mimicking pollutants (污染物质), ubiquitous (到处存在的) in the food chain, have two previously effects. They act on genes in the developing fetus (胎儿) and newborn to turn more precursor (前体) cells into fat cells, which stay with you for life. And they may alter metabolic (新陈代谢的) rate, so that the body saves calories rather than burning them. "The evidence now emerging says that being overweight is not just the result of personal choices about what you eat, combined with inactivity," says Retha Newbold of the National Institute of Environmental Health Sciences (NIEHS). " Exposure to environmental chemicals during development may he contributing to the obesity epidemic. "They are not the cause of extra pounds in every person who is overweight but environmental chemicals may well account for a good part of the current epidemic, especially in those under 50. The new thinking about obesity comes at a critical time politically. As the debate over health care shines a light on the country’s unsustainable spending on doctors, hospitals, and drugs, the obese make tempting scapegoats (替罪羊). About 60 percent of Americans are overweight or obese, and their health - care costs are higher: $3,400 in annual spending for a normal- weight adult versus $ 4,870 for an obese adult, mostly due to their higher levels of type 2 diabetes, heart disease, and other conditions. If those outsize costs inspire greater efforts to prevent and treat obesity, fine. But if they lead to demonizing (妖魔化) the obese - caricaturing (画成漫画讽刺) them as lazy pigs raising insurance premiums (保险费) for the rest of us -that’ s a problem, and not only for ethical reasons: it threatens to obscure (使不明显) that one potent cause of weight gain may be largely beyond an individual’s control. Robert Lustig believes the obesity epidemic is due to the exposure to environmental chemicals during development.
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