Class, Lass and Ass
Professor Tom was going to meet his students on the next day, so he wrote some words on the blackboard which read as follows: "Professor Tom will meet the class tomorrow."
A student, seeing his chance to display his sense of humor after reading the notice, walked up and erased the "c" in the word "class." The Professor noticing the laughter, wheeled around, walked back, looked at the student, then at the notice with the "c" erased--calmly walked up and erased the "l" in "lass", looked at the flabbergasted student and proceeded on his way.
班级、情人和蠢驴
汤姆教授打算第二天与他的学生见面，因此他在黑板上写道：“汤姆教授明天将和大家见面”。
一位学生看到这条通知后，觉得展示自己幽默感的机会来了，就走上前，将“class”中的“c”擦掉，将意思变为“汤姆教授明天将和情妇见面”。教授听到笑声，转过身走回来，看了看那位学生，又看看被改动过的通知，不动声色地走上前，把“lass”中的“l”擦掉，将意思改为“汤姆教授明天将和蠢驴见面”。看了看那位目瞪口呆的学生，教授扬长而去。
