Research on the integration and optimization design of universal health care system in China 并列题名:Research on the integration and optimization design of universal health care system in China Research on construction and system optimization of natural gas reserve system in China Research on the evaluation and optimization of the functional performance for the capital markets structure in China Research on the optimization and development of agricultural insurance system in China Research on the optimization of aquatic technologies promition system in China 并列题名:Research on construction and system optimization of natural gas reserve system in China current situation and development strategy of the primary health care system in China