The world can be changed by man's endeavor, and that this endeavor can lead to something new and better. No man can sever the bonds that unite him to his society simply by averting his eyes . He must ever be receptive and sensitive to the new ; and have sufficient courage and skill to novel facts and to deal with them . (Franklin Roosevelt , American President )

人经过努力可以改变世界，这种努力可以使人类达到新的、更美好的境界。没有人仅凭闭目、不看社会现实就能割断自己与社会的联系。他必须敏感，随时准备接受新鲜事物；他必须有勇气与能力去面对新的事实，解决新问题。(美国总统罗斯福. F.)