three engineers talking in a pub discussing the designer of the human body

electrical engineer "it must have an electrical engineer look at how the body is controlled by electrical impulses from the brain"

"no" said the mechanical engineer "it was a mechanical engineer look at the leverage principles employed by the muscles"

finally the civil engineer, " no" he said it was civil engineer who designed the human body, who else would have run a toxic waste pipe through a recreation area"

made me laugh
apologiesif you have heard it before