1which of the following is not involved in the transport of molecules by facilitated
diffusion?

a atp
b phospholipids
c protein channels
d concentration gradient

It depends on the surface of the levels. the rougher the surface, the greater is the frictional force. for rougher surfaces, you would need to exert greater force to move the object. the concept is that, you must overcome the frictional force in order to bring the object into motion. this is the reason why we add lubricants to the joints so they could easily move. this answer was on

Your answer is water because there is combined mass of water found on, under, and over the surface of a planet. your answer is water.