问题 单项选择题

地区 2007年度 2008年度
财政收入
(万元)
房地产开发
企业施工房屋面积
(万平方米)
财政收入
(万元)
房地产开发
企业施工房屋面积
(万平方米)
上海 20744792 10767 23587464 10784
山东 16753980 15165 1957054l 20099
湖南 6065508 8162 7227122 10716
吉林 3206892 4370 4227961 4965
新疆 2856600 2054 3610616 2639
天津 5404390 4837 6756186 5704
去南 4867146 4302 6140518 5368

2008年度“房地产开发企业施工房屋面积”最大的三个地区的面积之和比2007年度该三个地区之和增加了( )。

A.7615万平方米

B.7595万平方米

C.7535万平方米

D.7505万平方米

答案

参考答案:D

解析: 2007年和2008年的房地产开发企业施工房屋面积最大的三个地区都是上海、山东和湖南,所求为(10784-10767)+(20099-15165)+(10716-8162)=7505万平方米,可利用尾数法估计最后两位数字为(84-67)+(99-65)+(16-62)=17+34-46=05。

单项选择题
问答题

Going to the ballpark, visiting friends and playing bingo are simple diversions for many of us. But for the elderly, these social pastimes may play a critical role in preserving their physical and mental health.

(46) In fact, a new study suggests that the less time older people spend engaged in social activity, the faster their motor function tends to decline. "Everybody in their 60s, 70s and 80s is walking more slowly than they did when they were 25," says Dr. Aron Buchman, a neurologist at the Rush University Medical Center in Chicago and leading author of the study, which was published in the June 22nd issue of the Archives of Internal Medicine. (47) "Our study shows the connection between social activity and motor function--and opens up a whole new universe of how we might intervene. "

(48) An increasing body of evidence has suggested that participating in mentally stimulating activity, socializing frequently and exercising may help protect against age-related decline-at least cognitive decline. As early as 1995, neuroscientist Carl Cotman, who studies aging and dementia at the University of California at Irvine, published a paper in Nature showing that physical exercise produces a protein that helps keep neurons from dying and spurs the formation of new neural connections in the brain. (49) More recently, Cotman demonstrated in studies of elderly dogs and mice that enriching their social environment is associated with improvement in brain function.

Researchers are also finding that social activity may be linked to the same protective effect in people. A recent study of 2 500 adults ages 70 to 79, published in the journal Neurology, found that those who were able to stay mentally sharp were also those who exercised once a week or more, had at least a ninth grade literacy level and were socially active.

While further research needs to be done to establish the exact impact of social activity and exercise on specific age-related declines (50) it’s likely that a reduction in social activity may simply be a symptom of physical decline, since people may naturally withdraw from social engagement as they lose motor skills-most researchers would agree that it is not unreasonable to encourage seniors to get out there more. Only 10% of people over 65 get the recommended amount of exercise (at least 2. 5 to 5 hours a week), and given that seniors already tend to be more socially isolated than younger adults, it’s difficult to motivate them to become more active. "If you are alone, you are less likely to follow recommendations," notes Verghese. It might help, though, if you visit Grandma more often and let her know that a regular pastime may just help her stay fitter and sharper longer.

(47) "Our study shows the connection between social activity and motor function--and opens up a whole new universe of how we might intervene. "