单项选择题

Real advances in science have raised the question of just how long we might live. "Very long lives are not the distant privilege of (67) future generations," according to an analysis by the Danish gerontologist(老年学专家) Kaare Christensen and colleagues. They are the probable (68) of most people alive now in developed countries. Life (69) has been rising (70) a straight line for more than 165 years. (71) progress in the longest-living populations suggests that we are not (72) to a limit, and further rise in life expectancy seems (73)
In our lifetimes, we may (74) how to add years to our lives by (75) aging. Human growth hormone has been taken (76) that purpose ever since 1990. There’s no (77) evidence that it works. Even so, it is sold by antiaging companies, hawked everywhere on the Web, and (78) by the controversial American Academy of Anti-Aging Medicine, (79) biogeronto logists (生物老年学专 家) denounce the academy and its claims.
What happens when we have real antiaging pills that pass the tests of clinical (80) As bioethicists have begun to (81) , this is a problem that would make all our bioethical (82) to date look small. Stem cells, Cloning, Gene (83) , the privacy of genetic information, all these problems matter in themselves,but all of them would be (84) in the transformations of society and human nature that would be brought (85) by a significant success with the human life (86) .