I'll give you a question, please answer with step-by-step reasoning process.
If "Dirt biker on a professional riding course near an airport." does that mean that "Composed of dirt."?\nOptions:\n- yes\n- it is not possible to tell\n- no

it is not possible to tell
A man rides his dirt bike on a track by the airport.

.

Thus, the answer is it is not possible to tell