Teacher : What is a verb

Teacher : What is a verb?
Student : A verb is a valve found in
bicycle tyre.
Teacher : What are you saying?.
Student : It is a complete sentence.
Teacher : Are you mad?.
Student : It is a question.
Teacher : Don't be silly.
Student : It is an advice.
Teacher : Stop that nonsense.
Student : It is a command.
Teacher : You are an idiot.
Student : It is an insult!.
Teacher : Get out of my class.
Student : It is an order!
Teacher : Oh my God! What a shame!
Student : It is an exclamation.
Teacher : May God have mercy on you.
Student : It is a prayer sir!