奥巴马在亚利桑那州立大学2009年毕业典礼上的演讲
Acts of sacrifice and decency without regard to what’s in it for you — that also creates ripple effects — ones that lift up families and communities; that spread opportunity and boost our economy; that reach folks in the forgotten corners of the world who, in committed young people like you, see the true face of America: our strength, our goodness, our diversity, our enduring power, our ideals.
