Taking a cell, practically any cell, from your body, the theory goes, and through appropriate biological tinkering(摆弄) you can cause it to grow into a duplicate of yourself—identical from eyelashes to toenails. No need for procreational(生育的) sex any more(51) this system, you can neatly reproduce yourself without a(52). Human cloning, it is called. Science fact or science fiction? What would happen if human cloning became a(53)? One favorite scenario is the(54)of a new(55)of Hitlers—or Einsteins. Scientists quickly disclaim the possibility. 'It is more than genetic make-up that makes an individual.' Says Markert of Yale University, 'We are all products of a particular(56)era and of a special environment, with so many minute things(57)the way we develop each and every day, even in the womb, that a duplicate background--and therefore a duplicate(58)could never be created.' Already biologists studying the cell's(59)workings and the various methods of cloning have made discoveries that may ultimately lead to breakthroughs(60)the fight against cancer, control of the aging process, and the conquest of more than 100 presently incurable human genetic diseases. To(61)cloning-related research would mean closing the door(62)and important area of knowledge. To continue to probe the secrets of the cell, however, is perhaps to(63)the secret of human cloning. And, given the nature of man, if it can be done it will be done. What then is the(64)? Says Congressman Rogers: 'It is clear that human cloning is not yet possible. The day when it will be—if ever—is far(65). For now, at least, the benefits of cell-biology research outweigh the risks.'