“…Hoogesteger and Rivara think that farmers run, economic crimes, death/ escape/kidnapping of the head of the mutual aid society, natural disasters that cause the cooperative to fail to operate normally, abnormal computer network paralysis, mass petitions and demonstrations, and other cases that may cause great harm are the risks and unexpected risk events of mutual funds [17]. Nayak et al think that whether to develop big cities, medium cities, small cities, or small towns should be mainly regulated by the market, and the government can only guide them [18]. Delcroix believes that the development direction of urbanization in China is the development of medium-sized cities in urban circle, and at the same time, the further development of medium-sized cities will form a new urban circle [19].…”