84号选手：volunteer means to undertake a kind of obligation. it undertake a kind of obligation. it encourages devote, frindship, mutual aid, and making progress. （翻译：）志愿意味着主动承担某种责任和使命,大到汶川地震，北京奥运会再到街头巷尾，处处都能看到誓愿者的身影，
