Student failed the exam. He goes to his professor's office and asks him if he could get another chance.

"You failed the exam twice, young man. I'm sorry, but you won't get another chance." said the professor.

The student doesn't give up and says "What if I told you I could walk on the ceiling? Would you change my grade to D?"

The professor, amused, said "If you walk up that wall and onto the ceiling, I'll change your grade to D."

The student smiled and walked on the wall onto the ceiling and back. The professor was shocked but he promised to changed the grade, so he grabbed a pen without a word and then the student stopped him, saying "If I told you I could fly, would I get a B?"

The professor agreed without hesitation and soon watched the student levitate around the room.

As soon as he landed, he asked his teacher "If I piss on you and you'll still be dry... would I get an A?" The professor agreed. The student unzipped his pants and pissed on the teacher.

To the professor's surprise, he was all wet with urine. The student zipped his pants and said "I'll settle for a B."