Directions: There are 3 passages in this section. Each passage is followed by some questions or unfinished statement. For each of them there are four choices marked A., B., C., and D. You should decide on the best choice and write down the corresponding letter on the Answer Sheet. )

Passage Three

Several commentators and scientists have suggested that it might in some cases be ethically acceptable to clone existing people. One possibility is generating a replacement for a dying relative. All such possibilities, however, raise the concern that the clone would be treated as less than a complete individual, because he or she would likely be subjected to limitations and expectations based on the family’s knowledge of the genetic “twin.” Those expectations might be false, because human personality is only partly determined by genes. The clone of an extrovert（性格外向 的人） could have a quite different way of behavior. Clones of athletes, movie stars, entrepreneurs or scientists might well choose different careers because of chance events in early life.

Some people have also put forward the notion that couples in which one member is infertile might choose to make a copy of one or the other partner. But society ought to be concerned that a couple might not treat naturally a child who is a copy of just one of them. Because other methods are available for the treatment of all known types of infertility, conventional therapeutic avenues seem more appropriate. None of the suggested uses of cloning for making copies of existing people is ethically acceptable to my way of thinking, because they are not in the interests of the resulting child. It should go without saying that I am strongly opposed to allowing cloned human embryos to develop so that they can be tissue donors.

It nonetheless seems clear that cloning from cultured cells will offer important medical opportunities. Predications about new technologies are often wrong: societal attitudes change; unexpected developments occur. Time will tell. But biomedical researchers looking into the potential of cloning now have plenty to do.