Because of more job opportunities and a more convenient lifestyle, more and more young people desire to struggle for living in big cities. On the other hand, the senior people believe big cities can provide more advanced medical treatment, so they would leave the countryside when the disease comes. To sum up, big cities have to accept a high population at the time. Therefore, some people insist that the shortage of housing in big cities can cause severe consequences and only the government can release this pressure. From my perspective, these people's opinions convinced me.