Section B

Directions：In this section，you are going to read a passage with ten statements attached to it.Each statement contains information given in one of the paragraphs.Identify the paragraph from which the information is derived.You may choose a paragraph more than once.Each paragraph is marked with a letter.Answer the questions by marking the corresponding letter on AnswerSheet 2.

Exercise to Protect Aging Bodies—and Brains

A）We all know that exercise is good for you.Staying physically active helps keep your heart healthy and your muscles strong，and in cancer patients it has even been shown to ward off relapse（复发）.Now a series of independently conducted studies on the effects of exercise on healthy older adults，published in the Archives of Internal Medicine，confirms that logging time at the gym not only helps maintain good health but may even prevent the attack of chronic（慢性的）diseases，such as heart disease and dementia （痴呆）.

B）In one surprising trial，researchers led by Dr Teresa Liu-Ambrose at the University of British Columbia assigned 155 aging women to three separate groups at random and directly compared the cognitive（认知的）effects of two types of exercise：resistance training，done once or twice weekly，in which those who took part in the trial worked out with free weights and weight machines and did squats and lunges（弓步）， versus（与……相对）toning and balance exercises，which those who took part in the trial did twice a week.

C）By the end of the yearlong study，the women who weight-trained saw an improvement in their performance on cognitive tests of memory and learning as well as in executive functions such as decision-making and conflict resolution—women who trained once a week improved their scores in executive functioning by 12.6%—while those who did balance and toning exercises showed no such improvement.The muscle-strengthening exercise also helped the volunteers，ages 65 to 75，boost their walking speed，a commonly used indicator of overall health status in the elderly，as faster pace has been linked with lower death rate.

D）The Canadian researchers’findings were somewhat unexpected，given that previous studies on the issue have typically focused on aerobic（有氧的）exercise，which experts believe enhances cognitive function by promoting blood flow to the brain.Liu-Ambrose says her team speculated that anaerobic（厌氧的）weight training would have a similar effect for other reasons.First，a resistance-training regimen requires a considerable amount of learning，especially for elderly people who may not be accustomed to the equipment.To learn how to use dumbbells or a leg press correctly，for example，the volunteers were required to focus on the task at hand，master new techniques and retain new information about proper and safe use of equipment.Previous studies have shown that such learning can help older adults maintain mental acuity（敏锐）.

E）The women also had to remember their weight settings and adjustments to the seats and keep track of the number of repetitions they completed，says Liu-Ambrose.“There is a lot more learning involved that may not occur if you take up a walking program，”she says，noting that it took the volunteers a good two months to get comfortable with the equipment and the training regimen.In addition，Liu-Ambrose says，other studies have found that people who weight-train show an increase in blood levels of a growth factor that is important for maintaining skeletal mass.This factor，it turns out，also promotes nerve growth，which could be another way that resistance training boosts mental function.

F）In a second brain-function study，published in the same journal，scientists in Germany found that increased physical activity was associated with a lower incidence of dementia.In this study，researchers recruited 3，485 elderly residents in Bavaria and asked them about their physical activity.None of those who took part in the study had dementia at the start of the analysis，but after two years of follow-up，researchers found that those who exercised at least three times a week were half as likely to have developed dementia，compared with the people who reported no physical activity.Based on his results，says lead author Dr Thorleif Etgen，a professor of psychiatry（精神病学）and psychotherapy at München University，“it doesn’t make a big difference if you have moderate or high physical activity.The important message is that you do any activity.And even if you start late in life，at 60 or 70，there is a benefit，for it’s never too late to start exercising.”

G）The key words are“moderate or high”，according to another study that was published in the Archives of Internal Medicine.Dr Qi Sun，a researcher at Harvard School of Public Health，analyzed 13，000 women participating in the Nurses’Health Study and found that when it came to exercise，more was better. Compared with women who jogged for 20 minutes a week，those who jogged three hours a week or walked quickly for five hours a week were 76%more likely to age successfully，free of chronic illnesses such as cancer and heart disease，as well as mental and physical impairment（损伤）.Sun’s group found that this benefit occurred across all weight divisions，meaning that even among those who were overweight，women who exercised improved their odds of aging without chronic disease.The effects may apply across different age groups as well；the women were at least 60 years old by the time they enrolled in the study，and while Sun was not able to determine how long they had been exercising prior to that，the results suggest that the health benefits are not limited to the young.

H）That was the same message of the final exercise paper in the journal，by researchers at University of Erlangen-Nuremberg in Germany.In this trial，a group of 246 elderly women were assigned to an 18-month exercise regimen or wellness program at random.The women participating in the four-times-weekly exercise sessions，which involved aerobics and balance and muscle training，improved their bone mineral density by nearly 2%.The women in the wellness group，which focused on walking，muscle relaxation and breathing skills，had a 0.33%increase in bone mineral density over the same time period.

I）Despite the positive evidence，however，not all researchers are ready to suggest that exercise is a sure-fire method against mental decline or chronic disease in healthy people.To make that claim，a large， longer-term，controlled trial would be needed，in which those who took part in the trial are assigned to exercise or not at random，and are then followed for the development of chronic conditions such as cancer， heart disease or dementia.Still，says Dr Marco Pahor，director of the Institute on Aging at the University of Florida and author of a commentary（评论性书籍）on the studies appearing in the journal，“If you pool all the evidence together，the benefits of exercise seem promising.”

36.Experts believe that the aerobic exercises raise people’s cognitive function by stimulating blood blow to brain.

37.Learning of using the resistance-training equipment is good for the elderly people in that it can keep their mind acute.

38.According to the studies published in the Archives of Internal Medicine，exercise can keep the healthy elderly from getting some chronic diseases.

39.The result of Liu-Ambrose and his partners’research about the cognitive effects of two kinds of exercise on aging women shows that resistance training is good for promoting cognitive function.

40.In Liu-Ambrose’s research，muscle-strengthening exercises increased the walking speed of volunteers aged 65-75.

41.In Dr Marco Pahor’s opinion，according to all evidence provided，it proves that exercise can bring promising benefits.

42.According to the research done by University of Erlangen-Nuremberg，different types of exercises taken by elderly women have different effect on their bone mineral density in the same period.

43.According to Qi Sun’s research，women who take more exercise have little chance to get some chronic diseases in their process of aging.

44.German scientists find that doing more physical exercises can lower the rate of dementia.

45.Those who take part in Liu-Ambrose’s research take the toning and balance exercises twice a week.