A surfer catches a wave and tries to hold on as the surf collapses around him.
A surfer is riding waves at the beach.
A spectator is watching people surf.
Men are shooting their guns.
It was constructed in the year 1634.
A young woman driving a Porsche.
More than one definition.
Some dogs are drinking out of a lake.
Either an Analysis that covers a lot of cases or a very rigorous analysis