马克思对生产过剩危机的分析，并没有停留于经济现象的分析，而是深入到资本主义经济关系或经济制度中探寻根源。因此，马克思经济危机理论的创立(　　)

一个环形，外圆半径为12厘米，内圆半径为8厘米，这个环形的面积是多少平方厘米？

2的倒数是（   ）

阅读材料，完成下列要求。

       党的十八大以来，以***同志为核心的党中央将卫生与健康摆在保障和改善民生、加强社会建设的重要位置予以部署推进。党的十八届三中全会从经济社会发展全局出发，对继续深化医改作出了全面部署，明确提出要建立更加公平可持续的社会保障制度，深化医疗卫生体制改革。在此精神的指引下，健康中国建设得到极大推进。2015年10月，健康中国建设正式写入党的十八届五中全会公报。2016年10月，国务院颁布《“健康中国2030”规划纲要》，为推进健康中国建设，提高人民健康水平作出了战略部署。

结合材料，运用政治生活的知识，说明在推进健康中国建设中党如何发挥领导作用的。

    Everyone needs friends. Friends bring us happiness and hope in our lives. But the ability to make friends changes from person to person. To some people, making friends is easy, and to others it's very difficult.
    Making friends is a skill, and the first thing is to know how to get on with others. If you have trouble in making friends, maybe I can tell you how to do it.
    Realize your own good points. You have skills and talents(才能) that others will like.
    Believe that you are a good person and have something nice to share with others.
    Be humourous. Learn to laugh at yourself and your weakness. Remember to smile at others.
    Respect(尊敬) the others. Everyone has his own idea. Learn how to listen to others; ideas without trying to make them accept(接受) yours.
    Be kind. If you are kind to others, they will usually be kind to you. There are hundreds of little things you can do to show your kindness. Open the door for someone. Wave to a friend and so on.
    Don't complain(抱怨). Learn to accept what you can't change, and work hard to change what you can. No one is willing to hear your complaints all the time.
    Never give up. Even if you are faced with some closed-minded people, never give up. And try to find someone who will understand you.