先讲一个故事。早上,三位旅行者同时从旅馆出发。第一位旅行者带了一把伞,第二位旅行者拄了一根拐杖,第三位旅行者两手空空,什么都没有拿。傍晚归来,只见带伞的旅行者被雨淋了个湿透,拄拐杖的旅行者摔得个遍体是伤,那位什么也没拿的旅行者偏偏既没挨淋也没摔伤。对此,前二位旅行者百思不得其解,于是试探着询问第三位旅行者:“你怎么会平安无事呢?”第三位旅行者没有正面作答,微笑着问带伞的旅行者:“你为什么被淋湿而没摔伤呢”?带伞的旅行者说:“我因为有伞便放肆地在雨里走,不知怎 Tell a story first. In the morning, three travelers departed from the hotel at the same time. The first traveler brought an umbrella, the second traveler leaned on a cane, the third traveler was empty-handed and took nothing. Returned in the evening, I saw travelers with umbrellas was soaked with crutches, crutches traveler fell over and over again is injured, who did not take anything that tourists either did not suffer from the shower did not fall. In this regard, the first two travelers puzzled, then tempted to ask the third traveler: ”How can you be safe?“ The third traveler did not answer directly, smiling and asked with an umbrella Traveler: ”Why did you get wet without falling?“ The traveler with an umbrella said: ”I walk in the rain because of an umbrella, I do not know.