A person on a dirt-bike motorcycle wearing multicolored protective clothing and helmet spinning out on top of a sand dune with sand spurting out in a rooster tail behind the motorcycle .
A man is riding a bicycle .
A person on a dirt-bike motorcycle wearing multicolored protective clothing and helmet spinning out on top of a sand dune with sand spurting out in a rooster tail behind the motorcycle.
A man is riding a bicycle.
A dirt-bike motorcycle is different from a bicycle.
A dirt-bike motorcycle is different from a bicycle .