Continental drift: the gradual movement of the continents across Earth’s surface over time fossil: a trace of an ancient organism preserved within a layer or rock
theory: a well-tested, widely accepted explanation that combines several hypotheses and observations

It's cell theory. easy name i would think.

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