When gravity is the only force acting on an object the object is in what?
One answer is that it is in free-fall in a vacuum (to eliminate atmospheric drag). Another answer is that it is in orbit around another body. The object could be in inter-stellar space, essentially experiencing the balanced gravitational force of "everything". If you eliminate the "middle of space" solution, the object would have to be in a state of acceleration.
A seagull drops a clam while flying over a beach.
When the only force acting on a falling object is air resistance the object is said to be in free fall.?
No, that is false. "Free fall" means that the only force acting on an object is GRAVITY. Specifically, there may be no significant amount of air resistance. It's not quite possible for the only force acting on an object to be air resistance, since you can't really eliminate the effect of gravity. Though, if the object has the same density than the liquid or gas in which it is placed, the gravity may be cancelled…