A man in a black shirt and black jeans and a little boy are taking a look inside a green truck 's engine while it is parked in a grass field with a gas tank in front of it .
Chances are about even that a father is teaching his son about truck engines .
Chances are about even that a father is teaching his son about truck engines .
It is almost certain that a father is teaching his son about truck engines .
A father is teaching his son about truck engines .