2008年12月大学英语六级考试A卷真题及答案（1） Part Ⅰ Writing（30 minutes）
注意：此部分试题在答题卡1上 Part Ⅱ Reading Comprehension（Skimming and scanning）（15 minutes） Supersize surprise Ask anyone why there is an obesity epidemic and they will tell you that it's al down to eating too much and burning too few calories. That explanation appeals to common sense and has dominated efforts to get to the root of the obesity epidemic and reverse it/ yet obesity researchers are increasingly dissatisfied with it. Many now believe that something else must have changed in our environment to precipiate（促成）such dramatic rises in obesity over the past 40 years or so. Nobody is saying that the “big two”— reduced physical activity and increased availability of food—are not important contirbutors to the epidemic, but they cannot explain it all. Earlier this year a review paper by 20 obesity experts set out the 7 most plausible alternative explanations for the epidemic. Her they are. 1. Not enough sleep It is widely believed that sleep is for the brain, not the body. Could a shortage of shut-eye also be helping to make us fat? Several large-scale studies suggest there may be a link. People who sleep less than 7 hours a night tend to have a higher body mass index than people who sleep more, according to data gathered by the US National Health and Nutrition Examination Survey. Similarly, the US Nurses’ Health Study, which tracked 68,000 women for 16 years, found that those who slept an average of 5 hours a night gained more weight during the study period than women who slept 6hours, who in turn gained more than whose who slept 7. It’s well down that obesity impairs sleep, so perhaps people get fat first and sleep less afterwards. But the nurses’ study suggests it can work in the other direction too: sleep loss may precipiate weight gain. Although getting figures is difficult, it appears that we really are sleeping less. In 1960 people in the US slept an average of 8.5 hours per night. A 2002 poll by the National Sleep Foundation suggests that the average has fallen to under 7 hours, and the decline is mirrored by the increase in obesity. 2. Climate control We humans, like all warm-blooded animals, can keep our core body temperatures pretty much constant regardless of what’s going on in the world around us. We do this by altering our metabolic（新陈代谢的）rate,shivering or seating. Keeping warm and staying cool take energy unless we are in the “themo-neutral zone”, which is increasingly where we choose to live and work. There is no
denying that ambient tempreatures（环境温度）have chnaged in the past few decades. Between 1970 and 2000, the
average British home warmed from a chilly Could air conditioning in summer and heating in winter really make a difference to our weight? Sadly, there is some evidence that id does-at leat with regard to heating. Studies show that in comfortable tempretures we use less energy. 3. Less smoking Bad news: smokers really do tend to be thinner than the rest of us, and quitting really does pack on the pounds, though no one isn’t sure why. It probably has something to do with the fact that nicotine is an appetite suppressant and appears to u your metabolic rate. Katherine Flegal and colleagres at the US National Center for Health Statistics in Hyattsville, Maryland, have calculated that people kicking the habit have been respousible for a small but significant portuon of the US epidemic of fatness. From data colected around 1991 by the US National Health and Nutrition Examination Survey, they worked out that people who had never smoked. Among men, for example, nearly half of quitters were overweight compared with 37% of non-smokers and only 28% of smikers. 4. Genetic effects Yours chancesof becoming fatmay be set, at least in part, before yu were even born. Children of boese mothers are much more likely to become obest themselves later in life. Offspring of mice fed a high-fat diet during pregnancy are much more likely to become fat than the offspring of identical mice fed a normal diet. Intriguingly, the effect persists for two or three generations. Grand-children of mice fed a high-fat diet grow up fat even if their own mother is fed normally-so you fate may have been sealed even before you were conceived. 5. A little older… Some groupps of people just happen to be fatter than others. Surveys carried out by the US national center for health statisties found that adults aged 40to 79 were around three times as likely to be obese as younger people non-white females also tend to fall at the fatter end of thr spectreum: Mexican –american women are 30% more likelt than white women to be obsess, and black wmen have twice the risk. In the US, these groups account foe an increasing percentage of the population between 1970 and 2000 the US population aged 35 to 44 grew by 43% the proportion of Hispanic-americans also grew, from under 5% to 12.5% of the population, while the proportion of black Americans increased from 11% to 12.3% these changes may account in part for the increased prevalence of obesity. 6. mature mums Mothers around the world are getting older in the UK, the mean age fir aving a frist chils is 27.3,compared with
This would be neither here nor there if it were’t for the observation that having an older mother seems to be an independent risk factor for obesity. Results from the US national heart, lung and blood institute’s study found that the odds of a child being obese increase 14% for every five extra years of their mother’s age, though why this should be so is not entirely clear. Michael Symonds at the university of
Nottingham, UK, Found that first-born children have more fat than younger ones.
Ad family sizedecreases, firstbrons account for a greather share of the
population. In 1964, british women gave birth to an average of 2.95 children;
by 2005 that figure had fallen to 7. Like marrying like Just as people pair off according to looks, so they do for size. Lean people are more likely to marry lean and fat more likely to marry fat. On its own, like marrying like cannot account for any increase in obesity. But combined with others-particularly the fact that obesity is partly genetic, and that heavier people have more children-it amplifies the increase from other causes. 1. A) effects of obesity on people’s health B) the link between lifestyle an obesity C) New explanations ofr the obesity epidemic D) possible ways to combat the obesity epidemic 2. A) gained the least weight B) were inclined to eat less C) found their vigor enchanced D) were less susceptible to illness 3. A) it makes us sleepy B) it causes sleep
loss C) it increases our appetite D) it results from lack of sleep 4. A) it makes us stay indoors more B) it accelerates our metabolic rate C) it makes us feel more energetic D) it contributes to
our weight gain 5. A) it threatens their health B) it heightens their spirits C) it suppresses
their appetite D) it slows down their mwtabolism 6. A) heavy smokers B) passive smokers C) those who never smoke D) those who quit
smoking 7. A) the growing number of smokers among young people B) the rising proportion of minorities in its
population C) the increasing comsumption of high-calorie foods D) the omproving living standards of the poor people 8. according to the US National Heart, Lung and Blood Institute, the reason why older mothers’ children tend to be obese remains not entirely clear 9. according to Michael Symbonds, one factor contributing to the obesity epidemic is decrease of family size 10. when two heavy people get married,
chances of their children getting fat increase, because obesity is party genetiz |
