A)It made a series of sharp turns in the sky. B) It took off and landed on a football field. C) It proved to be of high commercial vale D) It stayed in the air for about two hours. 6. A) Inadequate funding B) The air pollution it produced. C) Engineering problems D) The opposition from the military. 7. A) It uses the latest aviation technology. B) It is more environmentally friendly. C) It is a safer means of transportation D) It flies faster than a commercial jet.