Airplanes are hard to fly. Airplanes cost a lot of money. Airplanes can travel very quickly. Airplanes take off from the airport.
I gave my students this multiple choice question: Which fact is a benefit of airplanes?

Only one answer is correct among these 4 choices:
- Airplanes are hard to fly.
- Airplanes cost a lot of money.
- Airplanes can travel very quickly.
- Airplanes take off from the airport.

Could you tell me which one is correct?

Airplanes can travel very quickly.