6.mature mums

　　Mothers around the world are getting older.in the UK,the mean age for aving a frist child is 27.3,compared with 23.7 in 1970 .mean age at frist birth in the US has also increased, rising from 21.4 in 1970 to 24.9 in 2000.

　　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-bron children have more fat than younger ones. As family size decreases, 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 1.79. in the US in 1976, 9.6% of woman in their 40s had only one chile;in 2004 it was 17.4%. this combination of older mothers and more single children could be contributing to the obesity epidemic.

　　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 an d 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 form other causes.

　　1. A)effects of obesity on people’s health

　　B)the link between lifestyle an obesity

　　C)New explanations for 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 enhanced

　　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 metabolism

　　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 consumption of high-calorie foods

　　D)the improving 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 Symonds, 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