Professor Laurie of Glasgow put this notice on his door：Professor Laurie will not meet his classes today． 

　　A student，after reading the notice，rubbed out thec． 

　　Later Professor Laurie came along，and entering into the spirit of the joke，rubbed out thel． 

　　班和笨驴 

　　格拉斯哥的劳里教授在门上贴了这样一个通知：劳里教授今天不会他的班。 

　　一个学生读了通知后，擦掉了字母c。 

　　后来劳里教授来了，也想开开玩笑，他擦掉了字母。