A smiling dark-skinned young man sits on a stool at his outdoor workbench and makes a hand gesture of `` two-thumbs-up '' .
There is a very good chance that a boy sits on his stool and is happy with the project he has just finished .
There is a very good chance that a boy sits on his stool and is happy with the project he has just finished .
It is highly unlikely that a boy sits on his stool and is happy with the project he has just finished .
A boy sits on his stool and is happy with the project he has just finished .