一位朋友讲了这么一个故事:在宿舍楼的后面,停放着一部烂汽车,每当晚上七点时,大院里的孩子们便攀上车厢蹦跳,嘭嘭之声震耳欲聋,大人们越管,众孩童蹦得越欢,见者无奈。这天,笔者的这位朋友来了,他对孩子们说:“小朋友们,今日你们比赛,蹦得最响的奖玩具手枪一支。”众童呜呼雀跃,争相蹦跳,优者果然得奖。次日,这位朋友又来到车前,说:“今天继续比赛,奖品为2粒奶糖。”众童见奖品直线下跌,纷纷不悦,无人卖力蹦跳,声音疏稀而弱小。第3天,朋友又对孩子们说:“今日奖品为花生米2粒。”众孩童纷纷跳下汽车,说:“不蹦了,不蹦了,真没意 A friend told such a story: in the back of the dormitory parking a bad car, every time at seven o’clock in the evening, the children of the courtyard climbed up the car bouncing, deafening voice deafening, adults more Tube, children jump more joyous, see helpless. On this day, I came to this friend, he said to the children: “Children, today you play, bang the loudest award toy pistol.” Children Tongao jump, competing jump, gifted really prize. The next day, the friend came to the car again and said, “Today’s race continues with two toffee prizes.” Children see the prizes plummeting and are unhappy, sprinting and soundless. On the third day, my friend said to the children again: “Today’s prize is two balls of peanuts.” All the children jumped off the car and said: "No jumping, no jumping, no effect