单选题
American presidents seem to age before our eyes. But the common belief that high-office stress grays our leaders faster than 26 may be a myth, new research finds. In fact, the majority of American presidents have lived longer than typical men of their times. That's not to 27 that chronic stress has no effect on a person's lifespan, but so does high social standing. The findings 28 to a body of research linking high status to better health: for instance, Oscar winners live longer than those who were only 29 ; and the longevity (长寿) effect is also seen in Nobel Prize winners. The new study, which was published in the Journal of the American Medical Association, analyzed the dates of birth, inauguration and death of all 34 past presidents who died of natural causes. The 30 lifespan for these men should have been 68 years, if they'd aged twice as fast during their years in office as the popular wisdom suggests they do. Instead, the study found, these presidents lived an average 73 years. And indeed, 23 of the 34presidents who died of natural causes lived longer than expected, compared with other men their age during their lifetimes. Some presidents 31 an exceptionally long time: Gerald Ford died at 93.5 years, and Ronald Reagan at 93.3. All 32 living presidents have already exceeded their life 33 , or are likely to do so. So why do people at the top of the hierarchy fare better than those below? 34 to wealth, education and the best health care of their times would seem to be obvious factors although medical attention seems to have actually killed President Garfield, who died from a fatal 35 introduced by his doctors' unsterile (未消过毒的) treatment techniques after he was shot by an assassin. A. Access B. add C. average D. boundary E. covered F. currently G. Entrance H. expectancy I. infection J. nominated K. ultimate L. usual M. persistently N. say O. survived