1、After a couple has had their first child，to their disappointment they become infertile and cannot have more children.Many couples have difficulty in having children，and sometimes it is impossible for couples to have children because they are infertile.Fortunately，cloning would allow these couples to
2、 have children.This is one reason why it is difficult to decide if cloning is ethical or not.The following are some of the reasons why cloning should be allowed.As just discussed，cloning can be used to help benefit those that cannot have children through the normal，natural way.It is the desire of mo
3、st couples to have children and when it is impossible to bear children of their own，some are willing to do anything to have a child.Cloning will allow them to have a child or many children that have the genetic pattern of one of the parents.Through cloning，research can progress.We can learn enough t
4、o produce human organs without having to produce human beings.We may develop technology to allow easier genetic testing and fixing problems such as spinal cord injuries，cancer，and many more.Cloning organs for organ transplants is one of the major practical reasons that cloning should be allowed.Ther
5、e is always a high demand for organs.Some argue for the cloning of humans to create spare body parts.Others talk of just wanting to clone an organ to replace an imperfect organ.Rejuvenation is also a key argument for advocates of cloning.Human cloning may one day cure heart attacks.Some scientists believe that by injecting cloned healthy heart cells into damaged heart tissue will lead to healing of the heart.Notes1infertile adj.未生育的2ethical adj.伦理的3genetic adj.基因的4transplant n移植5rejuvenation n返老还童