1 . The benefits of regular exercise are well documented but there’s a new bonus to add to the ever-growing list. New researchers found that middle-aged women who were physically fit could be nearly 90 percent less likely to develop dementia in later life, and as they did, it came on a decade later than less sporty women.
Lead researcher Dr. Helena Horder, of the University of Gothenburg in Sweden, said : "These findings are exciting because it’s possible that improving people's cardiovascular （心血管的）fitness in middle age could delay or even prevent them from developing dementia. "
For the study, 191 women with an average age of 50 took a bicycle exercise test until they were exhausted to measure their peak （最大值的） cardiovascular capacity. The average peak workload was measured at 103 watts.
A total of 40 women met the criteria for a high fitness level, or 120 watts or higher. A total of 92 women were in the medium fitness category; and 59 women were in the low fitness category, defined as a peak workload of 80 watts or less, or having their exercise tests stopped because of high blood pressure, chest pain or other cardiovascular problems.
These women were then tested for dementia six times over the following four decades. During that time, 44 of the women developed dementia. Five percent of the highly fit women developed dementia, compared to 25 percent of the women with medium fitness and 32 percent of the women with low fitness.
"However, this study does not show cause and effect between cardiovascular fitness and dementia, it only shows an association. More research is needed to see if improved fitness could have a positive effect on the risk of dementia and also to look at when during a lifetime a high fitness level is most important. " She also admitted that a relatively small number of women were studied, all of whom were form Sweden, so the results might not be applicable to other groups.
1. What is on the ever-growing list mentioned in the first paragraph?| A．Positive effects of doing exercises. |
| B．Exercises suitable for the middle-aged. |
| C．Experimental studies on diseases. |
| D．Advantages of sporty woman over man |
| A．To predict their maximum heart rate. |
| B．To assess their cardiovascular capacity |
| C．To change their habits of working out |
| D．To detect their potential health problems |
| A．It aimed to find a cure for dementia. |
| B．Data collection was a lengthy process. |
| C．Some participants withdrew from it. |
| D．The results were far from satisfactory. |
| A．More Women Are Exercising to Prevent Dementia |
| B．Middle-Aged Women Need to Do More Exercise |
| C．Fit Women Are Less Likely to Develop Dementia |
| D．Biking Improves Women's Cardiovascular Fitness |
2 . The United States rose to global power on the strength of its technology, and the lifeblood that technology has long been electricity. By providing long-distance communication and energy, electricity created the modern world. Yet properly understood, the age of electricity is merely the second stage in the age of steam, which began a century earlier.
"It is curious that no one has put together a history of both the steam and electric revolutions." writes Maury Klein in his book The Power Makers, Steam, Electricity, and the Men Invented Modern America. Klein, a noted historian of technology, spins a narrative so lively that at times it reads like a novel.
The story begins in the last years of the 18th century in Scotland, where Watt perfected "the machine that changed the world". Klein writes, "America did not invent the steam engine, but once they grasped its passwords they put it to more uses than anyone else. "
Meanwhile, over the course of 19th century, electricity went from mere curiosity to a basic necessity. Morse invented a code for sending messages over an electromagnetic circuit. Bell then gave the telegraph a voice. Edison perfected an incandescent bulls that brought electric light into the American home.
Most importantly, Edison realized that success depended on mass electrification, which he showed in New York City. With help from Tesla, Westinghouse's firm developed a system using alternating current, which soon became the major forms of power delivery.
To frame his story, Klein creates the character of Ned, a fictional witness to the progress brought about by the steams and electric revolutions in America during one man's lifetime. It's a technique that helps turn a long narrative into an interesting one.
1. What is Klein's understanding of the age of electricity?| A．It is closely linked to the steam age. |
| B．It began earlier than proper thought. |
| C．It is a little-studied period of history. |
| D．It will come to an end sooner or later. |
| A．He was born in New York City. | B．He wrote many increasing stories, |
| C．He created an electricity company. | D．He lived mainly in the 19th century. |
| A．A biography. | B．A book review. | C．A short story. | D．A science report. |
