问题描述：
英语翻译
Healthcare system,
Socio-political environment,
Public health,
Unplanned readmissions,
Unplanned return to the operating theatre,
Hospital avoidance program,
Economies of Scale,
Clinical networks.
用英文来解释英文（名词解释）。比如Healthcare system是医疗保健系统，医疗保健系统的名词解释用英文来表达。上面的英文全部用英文的形式来名词解释
问题解答：
我来补答
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？
