One day,after school the teacher says to his students:“Tomor

One day,after school the teacher says to his students:“Tomorrow morning if anyone of you can answer my first questions,he or she can go home early.”
The next day,when the teacher comes into the classroom,he finds the blackboard very dirty.He is very angry and asks:”Who did it?Please stand up!” “It’s me.” Says Tom.“ Now ,I can go home.Goodbye.Sir!”