听力原文： It used to be that mentally retarded children were treated like criminals, nor was there any distinction made between the mentally retarded and the insane. Both were simply locked away in institutions where conditions differed little from those in prisons. The children were abused. Medical and nutritional needs were neglected, and no attempt was made to educate them. Today, the outlook for the mentally retarded has improved greatly. We have learned that although it requires a great deal of time and expense, these unfortunate youngsters can be taught to play a useful role in society. One of the newest approaches to the problem of mental retardation is called the group home treatment. The group home allows both mentally retarded children and adults to live in private homes under the supervision of one or more specially trained coordinators. One reason for this approach is to humanize the residencies so that the mentally retarded do not feel that they are being hidden away. Middle-class and upper middle-class residential areas are chosen for these group homes. The homes adapt the children to normal life, and at the same time they adapt normal people to the retarded. The purpose is not to replace the family but to establish a similar environment. (33)