sentence: A boy demonstrates how to ride a skateboard in the street through example. sentence:   A boy stands, outdoors,  holding a skateboard in his arms and then puts the board down and begins to step on it. sentence:   The boy  then stands on the board rocking back and forth on it. sentence:   The boy then exhibits upper body twists while standing on the skateboard and eventually pushes off and rides into the street on the skateboard. sentence: The boy then returns to the curbside and puts one foot on the board and the other on the ground as he stands still.