Tough JobA professor watched while a mechanic removed engine parts from his car to get to the valves. A surgeon, waiting for his car being repaired, walked over to observe the process. After they introduced themselves, they began talking and the talk turned to their lines of work.
"You know, doctor," the professor said, "I sometimes believe this type of work is complicated as the work we do."
"Perhaps," the surgeon replied. "But let's see him do it when the engine is running!"