单选题
A. for B. on C. stress D. profits E. made F. connection G. take H. indicating I. benefits J. sufficient K. efficient L. habits M. as N. improved O. emphasizing In the recent past, medical research have shown that heart disease is associated with certain factors in our day-to-day lives: with stress, with smoking, with poor nutrition, and with a lack of exercise. Doctors and other health experts have been 42 the fact that we can often reduce the risk of heart disease by paying more attention to these factors. More and more people are realizing that there is a 43 between heart disease and the way they live. As a result of this new awareness, attitudes towards health are changing. In the past, people tend to think that it was 44 for good health to have a good doctor who could be relied on to know exactly what to do when they become ill. Now they are realizing that merely receiving the best treatment 45 illness and injury is not enough. They are learning that they must 46 more responsibility for their own health. Today many people are changing their dietary 47 and eating food with less fat and cholesterol. Many are paying more attention to reducing 48 in their lives. The number of smokers in the US is now far below the level of a lot of years ago 49 many people succeed in breaking the habit and as fewer people take it up. More and more are aware of the 50 of regular exercise like walking, running or swimming, some have begun to walk or ride bicycles to work instead of driving. Millions have become members of health clubs and have 51 health club one of the fastest growing businesses in the US today. And now the beneficial effects of these changing attitudes and behaviors are beginning to appear: an encouraging decrease in deaths from heart disease.