style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/B． Success breeds imitators. Amazon is about to be attacked by a squadron of would-be Kindle killers being brought to market by some of the biggest names in consumer electronics and publishing. To complicate the increasingly competitive landscape even further, Apple and, according to rumor, Microsoft are working on tablet computers that could prove to be handy e-readers but with more functions and features, such as video display capability and full web browsers. "2009 is a breakout year fore-readers," says Sarah Rotman Epps, an analyst with Forrester Research."But we're still in the early stages."
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/C． The early stages have lasted a longtime. E-readers have been around for more than a decade, but the devices weren't popular due to high cost, proprietary (专利的) display formats and the reluctance of book publishers to sell digital versions of their best-selling titles. Now, just as digital music was driven into the mainstream by Apple's iPod and iTunes, Amazon's Kindle andonline bookstore, which sells more than 350,000 titles, are proving there's amass market for e-books. Total industry revenue from digital-book downloads has risen 149% this year, according to the Association of American Publishers,while e-reader sales are expected to reach 3 million by Dec.31, according to For rester Research. Almost a million of the devices could be sold during the upcoming holiday season alone. In 2010, sales are projected to double, to 6 million.That kind of growth is hard to come by in the recession-wracked technology industry, and a crowd is starting to gather. Around the world, at least 17 e-readers are in development or already on the market.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/D． Among the better-known entrants is Asustek -- the Taiwanese company of China practically invented the netbook category with its ASUS Eee-PC, and it is working on a product called the Eee-reader that it hopes to have on the market in time for Christmas. South Korea's two powerhouse consumer-electronics companies, Samsung and LG Electronics, are wading in too. Samsung earlier this year introduced a reader called the Papyrus in South Korea; reports circulating in the technology blogosphere say LG is developing a prototype with a large,11.5- inch (diagonal） flexible screen. Meanwhile, Japan's Fujitsu has released the world's first dedicated e-reader with a colour  screen, although so far the device is only available in Japan.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/E． It isn't just tech companies that are joining the fray. Bricks-and-mortar bookseller Barnes & Noble, which in the US offers access to 750,000 e-books on its website, is rumored to be pondering the development of its own e-reader to rival the Kindle. (The retailer already has a partnership to sell e-readers made by IREX, a spin-off of Holland's Royal Philips Electronics.)
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/Major newspaper and magazine publishers,which are suffering mightily from the loss of subscribers and advertisers to the recession and the Internet, are also getting involved. News Corp. chairman and CEO Rupert Murdoch, owner of The Wall Street Journal, is reportedly considering a deal with Japanese consumer-electronics giant Sony, which in 2004 introduced the first commercially viable e-reader, to use a black-and-white display technology called electronic ink (also used by the Kindle. Sony is rolling out a new family of e-readers, including a pocket- size version and one with a large screen that's geared toward newspapers and magazines.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/F． One reason e-readers are getting traction is that competition is driving down prices. Amazon has cut the price of the Kindle by $100 over the past six months, to $259. As e-readers proliferate(激增) and price disparities narrow, manufacturers are trying to differentiate their products by adding features such as MP3 players and touch screens. The eSlick by Foxit,based in Fremont, Calif., allows users to listen to songs while reading .Asustek recently unveiled a prototype e-reader with two screens, which would more closely duplicate the traditional reading experience, although the devicethat the company expects to release later this year will have a single screen.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/G． At the same time, new display technologies are emerging that promise to improve battery life and make devices more portable and easier to read. UK-based Plastic Logic hopes to introduce nextyear the first e-reader with a plastic screen that will reduce glare and be less prone to cracking when dropped by ham-fisted owners. Electronic-ink technology is set to move from black and white to colour by the end of 2010.Even video is on the horizon. "We'll see a range of models start to appear over the first half of 2010 offering a range of different reading and productivity experiences," says Neil Jones, CEO of UK-based In teread, which in May launched
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/a $249 e-reader called the COOL-ER.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/H. Newcomers will have a hard time breaking Amazon's chokehold in the US, where the company controls 60% of the e-reader market, according to Forrester Research. But the edge Amazon gained when it launchedthe Kindle could be blunted by evolving technology and changing consumer needs.Currently, more people read e-books on their smart phones than they do on dedicated devices like e-readers.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/I. And there's the looming threat posed by next-generation tablet computers. Apple, the king of cool handheld devices, is rumored to be readying a tablet computer with all the functions of a laptop aswell as iPhone-like touch capabilities for release early next year. Microsoft has been secretive about its plans for a tablet, but a video making the rounds of the blogosphere shows a dual-LCD-screen prototype that closes like a book."E-readers are a transitional technology," says Rotman Epps of Forrester Research. It means that just as the e-reader is taking off, it may be becoming obsolete.

style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/B． The World Health Organization recommends using a formula that takes into account a person's height and weight.-The"Body Mass Index" (BMI) is calculated by dividing the person's weightin kilograms by the square of their height in meters, and is thus given inunits of kg/m2. A BMI of 18.5-24.9 is considered to be the healthiest. A BMI of between 25 and 29.9 is considered to be overweight, while a BMI of over 30 is considered to be obese.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/C． However, it is recognized that this definition is limited as it does not take into account such variables as age,gender and ethnic origin, the latter being important as different ethnic group shave very different fat distributions. Another shortcoming is that it is not applicable to certain very muscular people such as athletes and bodybuilders,who can also have artificially high BMIs. Agencies such as the National Cholesterol Education Program (NCEP) in the USA and the International Diabetes Foundation (IDF) are starting to define obesity in adults simply in terms of waist circumference. 
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/Health Effects of Obesity
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/D． Over 2000 years ago, the Greek physician Hippocrates wrote that" persons who are naturally very fat are apt to die earlier than those who are slender". This observation remains very true today.Obesity has a major impact on a person's physical, social and emotional well-being. It increases the risk of developing diabetes mellitus type 2("mature onset diabetes") and also makes Type 2 diabetes more difficult to control. Thus weight loss improves the levels of blood glucose and blood fats, and reduces blood pressure. The association between obesity and coronary heart disease is also well-known. 
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/Cancer
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/E． Furthermore, in 2001 medical researchers established a link between being overweight and certain forms of cancer, and estimated that nearly 10,000 Britons per year develop cancer as a result ofbeing overweight. This figure was made up of 5,893 women and 3,220 men, with the strongest associations being with breast and colon cancers. However, it is thought that being overweight may also increase the risk of cancer in there productive organs for women and in the prostate gland for men.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/F． The link between breast cancer and nutritional status is thought to be due to the steroid hormones, oestrogen and progesterone, which are produced by the ovaries, and govern a woman's menstrual cycle. Researchers have found that the more a woman eats, or the more sedentary her lifestyle, the higher are the concentrations of progesterone. This link could explain why women from less affluent countries have lower rates of breast cancer. Women from less affluent nations tend to eat less food and to lead life styles which involve more daily movement. This lowers their progesterone level, resulting in lower predisposition to breast cancer.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/G． The Times newspaper, in 2002 reported that obesity was the main avoidable cause of cancer among non-smokers in theWestern world! 
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/Aging
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/H. Research published by St Thomas'Hospital, London, UK in 2005 showed a correlation between body fat and aging,to the extent that being obese added 8.8 years to a woman's biological age. The effect was exacerbated by smoking, and a non-overweight woman who smokes 20 cigarettes a day for 20 years added 7.4 years to their biological age. The combination of being obese and a smoker added at least ten years to a woman's biological age, and although the study only involved women, the lead researcher Professor Tim Spector believes the finding would also apply to men.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/I. The aging effect was determined by measuring the length of telomeres, tiny "caps" on the ends of chromosomes,which help protect the DNA from the ageing process. Indeed, telomeres have been dubbed the "chromosomal clock" because, as an organism ages, they become progressively shorter, and can be used to determine the age of the organism. Beyond a certain point, the telomere becomes so short that it is nolonger able to prevent the DNA of the chromosome from falling apart. It is believed that excess body fat and the chemicals present in tobacco smoke release free radicals which trigger inflammation. Inflammation causes the production of white blood cells which increases the rate of erosion oftelomeres.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/Dementia
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/J. Recent research (2005) conducted in the USA shows that obesity in middle age is linked to an increased risk of dementia, with obese people in their 40s being 74% more likely to develop dementia compared to those of normal weight. For those who are merely overweight, the lifetime risk of dementia risk was 35% higher.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/K. Scientists from the Aging Research Centre at the Karolinska Institute in Sweden have been able to take information such as age, number of years in education, gender, body mass index, blood pressure level, physical activity and genetic factors, assigning each a risk score. They then used this information to devise a predictive test for dementia. This test will enable people at risk, for the first time, to be able to affect life style changes which will reduce their risk of contracting dementia.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/Other Problems
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/L. The world-wide upsurge in obesity,particularly in children, is of major economic concern, liable to drain economies. Of further concern is that research conducted in Australia and published in 2006, shows that up to one third of breech pregnancies were undetected by the traditional "palpation" examination, the danger being greatest for those women who are overweight or obese—a growing proportion of mothers. This means that such women are not getting the treatment required to turn the baby around in time for the birth, and in many cases require an emergency caesarean section.
style=color: rgb(51, 51, 51); font-family: "Microsoft YaHei"; white-space: normal; background-color: rgb(250, 250, 250);/M. This is a true health-care crisis, far bigger than Severe Acute Respiratory Syndrome (SARS) and ultimately, even bigger than AIDS.