[单项选择]Prison Systems _________(46). A long time ago, prisons were established for detention only. People were kept in prison to wait for torture, death, or other cruel punishment. Near the end of the Middle Ages the people of Europe became angry about the cruel acts of that system, and disagreed strongly. Therefore, less cruel techniques of punishment were used. ______ (47). The early settlers of America brought with them the idea of isolating prisoners._________(48). After a long isolation, the prisoners could be allowed to go because they would not do any more wrong acts. At the end of the 18th century, however, a religious stopped that system. About the time of the American Civil War, a new place for young offenders was built in N.Y. _________(49). At the end of the 19th century, a new idea was introduced. It allowed prisoners to work together during the day. It also reduced problems of administration._________(50). A. For example, people were sent away from their