并列题名：Governance of ecological environment in wind gap regions of mega-cities Governance of ecological environment in wind gap regions of mega-cities 并列题名：Study of ecological environment during the Qin and Han dynasties 并列题名：Protection of the ecological environment in Miaojiang region by the Qing government Community of ecological environment in landscape method 并列题名：Urban ecological environment and meteorology 并列题名：Research on ecological environment industry