What are the factors that affect the strength of a frictional force? the acceleration of the object the color and density of an object the bouyant forces acting on an object the mass of an object and how rough the surface is

What changes occur in the brain during the teenage years? 25 points, someone me out!a.) thinking becomes slower as the brain grows larger. b.) connections between neurons become stronger and faster. c.) unused neurons fuse together to form larger, better functioning neurons. d.) more neurons are developed.