14年12月英语六级长篇阅读预测题

2014-11-26 17:34:38 字体放大:  

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 lifestyles which involve more daily movement. This lowers their progesterone level, resulting in lower predisposition to breast cancer.

G: The Times newspaper, in 2002 reported that obesity was the main avoidable cause of cancer among non-smokers in the Western world!

Aging

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.

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 no longer 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 of telomeres.

Dementia

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.

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 lifestyle changes which will reduce their risk of contracting dementia.

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