Once I received a thank-you note from a friend whom I had helped. In the envelope were five lottery tickets that had been scratched, revealing the numbers. "Thank you very much for your help," the note read. "As a gift, I bought you some lottery tickets- sorry you didn't win. "

　　有一次，我收到一封感谢信，是一个我曾帮助过的朋友寄来的。信封内有五张彩票，都被刮过了，露出了数字。“非常感谢您的帮助，”信上写道，“作为礼物，我给您买了些彩票——真遗憾，您没中奖。”