英语翻译Healthcare system,Socio-political environment,Public hea

A health system, also sometimes referred to as health care system or healthcare system is the organization of people, institutions, and resources to deliver health care services to meet the health needs of target populations。There is a wide variety of health systems around the world, with as many histories and organizational structures as there are nations。 In some countries, health system planning is distributed among market participants。 In others, there is a concerted effort among governments, trade unions, charities, religious, or other co-ordinated bodies to deliver planned health care services targeted to the populations they serve。 However, health care planning has been described as often evolutionary rather than revolutionary。Public health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals。In microeconomics, economies of scale are the cost advantages that enterprises obtain due to size, with cost per unit of output generally decreasing with increasing scale as fixed costs are spread out over more units of output。 Often operational efficiency is also greater with increasing scale, leading to lower variable cost as well。 再问： 大神 请问只有四个吗？