The Human Body
Three freshman engineering students were sitting around one day arguing about who might have designed the human body.
The first one said, "It must have been a mechanical engineer. The human body has all those levers and pivots and stuff - a mechanical engineer must have designed all that."
The second one said, "No, it had to have been an electrical engineer. The complex way the nerves are wired up to the brain must have been designed by an electrical engineer."
Then the third one said, "No, it was a civil engineer. Who else would have run a waste water line through the recreational area?"