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.

the correct answer is - d. china has a large and growing population.

the fact that china has a large (the biggest) population, and it is still growing, doesn't hinder the agriculture production in the country. in fact, it can for increased production in the agriculture, since there's more labor force, as well the sheer mass of people produces lots of scientists that come up with new inventions as to how to improve this sector. nice example is the inner mongolia region in china, in general dominated by the gobi desert, but few scientist came up with a nice idea as to how to make the region productive by using plants that are very resistant to droughts, so lots of people have been employed, and the region is becoming greener and greener each year, and the production of food in this region is also increasing.