<http://schema.org/description>
"Long before the Wright brothers guided their fixed-wing aircraft over the North Carolina dunes, daredevils and engineers worked to decode the secrets of sustained heavier-than-air human flight. What do you know about the physics of flight?"^^<http://www.w3.org/2001/XMLSchema#string>
<http://science.howstuffworks.com/transport/flight/modern/physics-of-flight-quiz18.htm>