Body Parts?

Three Engineers are debating the issue of who would be more likely to build the human body. One starts by saying that with all of the body's levers and joints a Mechanical Engineer would have been most likely. The second argued that an Electrical Engineer would have made the human body with all of its electrical impulses throughout the nervous system. The last one smirked before saying that it was obviously a civil engineer, who else would have put a recreation center so close to a major waste disposal site.