A boy is airborne on a bicycle above an urban walkway near a handrail .
A boy riding his skateboard on the walkway .
A boy is airborne on a bicycle above an urban walkway near a handrail.
A boy riding his skateboard on the walkway.
The boy is either riding a bicycle OR a skateboard. If he is airborne he is not "on" the walkway.
The boy is either riding a bicycle OR a skateboard . If he is airborne he is not `` on '' the walkway .