Class, Lass and Ass
班级、情人和蠢驴

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.
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”。

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.

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。