Mechanic VS Doctor..

Marvellous answer

A mechanic was removing the cylinder heads from the motor
of a car when he spotted the famous heart surgeon in his
shop, who was standing off to the side, waiting for the
service manager to come to take a look at his
car.

The mechanic shouted across the garage,"Hello Doctor!!
Please come over here for a minute."

The famous surgeon, a bit surprised, walked over to the
mechanic.

The mechanic straightened up,
wiped his hands on a rag and asked argumentatively, "So
doctor, look at this. I also open hearts, take valves out,
grind 'em, put in new parts, and when I finish this will
work as a new one. So how come you get the big money, when
you and me is doing basically the same work?
"

The doctor leaned over and whispered to the
mechanic....

Try
operating while the engine is running.....