None, that's what students are for.
Only one, but he'll just hire a ghostwriter to do it for him.
You cant count them when its dark
A heart surgeon takes his Cadillac to his mechanic to get his engine fixed. When he returns a few days after to pick up the car, the mechanic calls him over to show him something. He says, "Okay Doc, I've changed the seals out and fixed everything up but I have one question. The engine is to the car as the heart is to the body. Why is it that you make some much more money than me?" The doctor examines the engine carefully and says, "try fixing it while the engine is running."
Woah woah woah... I never said there was a lightbulb!
He wrote "1 + 0 = 0" and then spent the rest of the lesson trying to rub one out...
Miss Carriage
Teacher: Why is your paper blank? Student: Sometimes silence is the best answer ! :D :D
Student: H, I, J, K, L, M, N, O. Teacher: That's not what I taught you. Student: But you said the formula for water was...H to O.