In many countries in the process of industrialization, overcrowded cities present a major problem. Poor conditions in these cities, such as lack of housing, inadequate sanitation(卫生)and lack of employment, bring about an increase in poverty, disease and crime. The over-population of towns is mainly caused by the drift of large numbers of people from the rural areas. These people have become dissatisfied with the traditional life of farming, and have come to the towns hoping for better work and pay. One possible solution to the problem would be to impose registration on town residents. Only officially registered residents would be allowed to live in the towns and the urban population would thus be limited. In practice, however, registration would be very difficult to enforce (推行); it would cause a great deal of resentment (不满), which would ultimately lead to violence. The only long-term solution is to make life in the rural areas more attractive, which would encourage people to stay there. This could be achieved by providing encouragement for people to go and work in the villages. Facilities in the rural areas, such as transport, health and education services should be improved. Education should include training in improved methods of farming and other rural industries, so as to develop a more positive attitude towards rural life. The improvement of life in the villages is very important, because the towns themselves cannot be developed without the simultaneous or previous development of the rural area.According to the writer, the problem with crowded cities will be solved if_______. A. traditional methods of farming are well keptB. conditions in rural areas are much improvedC. the government can provide more jobsD. violence could be controlled in cities