Study on the double dual structure of urban and rural areas in China Study on the basic public services in urban and rural areas of Beijing the differences between urban and rural areas in China 并列题名：Study on the basic public services in urban and rural areas of Beijing Study on livelihood guarantee for low-income households in urban and rural areas in China Study on comprehensive management of urban and rural environment in China Research of the agriculture production and development of urban and rural areas in ancient China 并列题名：Study on livelihood guarantee for low-income households in urban and rural areas in China Study on the coordinated development of industrial structure evolution and urbanization in China Research on the evolution of spatial structure of three major urban agglomerations in China