Research on index system of sustainable development of telecom operator ReseaRch on the hieRaRchical stRuctuRe of the metRopolitan system and economic development of the pRovincial capital uRban ciRcle in shandong Research on layout of China leisure agriculture based on sustainable development Trends Analysis of Graphene Research and Development A research on environmental education development China's Land System and Its Extraordinary Infrastructure Development Research on the path of transitional development of liquor industry based on the background of "Internet +" A research on promoting green development by green finance in Guizhou province ReseaRch on GRadient Valuation techniques Based on the system of intellectual PRoPeRty RiGhts finance ReseaRch on challenges and stRategies foR china‘s gReen economy development