flaps — something flat and broad that is attached at one side only and hangs loosely or covers an opening: the flap of an envelope; the flap of a pocket.
stunts — to use in doing stunts: to stunt an airplane.
errors — Third-person singular simple present indicative form of error.
ruins — ruins, the remains of a building, city, etc., that has been destroyed or that is in disrepair or a state of decay: We visited the ruins of ancient Greece.