Which statement is true about the forces involved in an ornithopter and a pterosaur taking off

The flapping of wings create forces which are caused by usage of two muscles pectoralis and supracoracoideus.

Explanation:

An ornithoper is a bird which fly by the movement of its wings. These creature fly by using their muscles. They may differ in flying method from one another but their way of flapping and flying is same. Pterosaur are the close cousins of dinosaurs who used to flap their wing to fly. They are not birds instead they are a form of reptiles who fly.

frogs. the lower the ph the higher the acid content. frogs have the highest tolerance in this scenario.