题目内容
阅读理解：阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项．
America is a country on the move. In unheard of numbers, people of all ages are exercising their way to better health. According to the latest figures, 59 percent of American adults exercise regularly-up 12 percent from just two years ago and more than double the figure of 25 years ago. Even non-exercisers believe they would be more attractive and confident if they were more active.
It is hard not to get the message. The virtues(优点) of physical fitness are shown on magazine covers, postage stamps, and television ads for everything from beauty soaps to travel books. Exercise as a part of daily life did not catch on until the late 1960s when research by military doctors began to show the health benefits of doing regular physical exercises. Growing publicity(宣传) for races held in American cities helped fuel(给……加燃料) a strong interest in the ancient sport of running. Although running has leveled off in recent years as Americans have discovered equally rewarding(值得做的)and sometimes safer forms of exercise, such as walking and swimming, running remains the most popular form of exercise.
As the popularity of exercise continues to mount, so does scientific evidence(证明) of its health benefits. The key to fitness is exercising the major muscle groups vigorously(强有力地) enough to approximately(大约) double the heart rate and keep it doubled for 20 to 30 minutes at a time. Doing such physical exercises three times or more a week will produce considerable improvements in physical health in about three months.
1．According to the passage, what was the percentage of American adults doing regular physical exercises two years ago?
[ ]
2．Which of the following is closest in meaning to the underlined phrase “leveled off”?
[ ]
A．become very popular
B．stopped being popular
C．reached its lowest level in popularity
D．stopped increasing in popularity
3．It can be learnt from the passage that the health benefits of exercise ________.
[ ]
A．are yet to be proved
B．are to be further studied
C．are supported by scientific evidence
D．are self-evident
4．Which of the following would be the best title for the passage?
[ ]
A．Different Forms of Exercise
B．Exercise－The Road to Health
C．Scientific Evidence of Health Benefits
D．Running－A Popular Form of Sport
