Sarah wants to know which brand of nail polish lasts the longest without chipping. she buys 4 types of nail polish – essie (which she normally uses,) butter, opi, and sally hansen. every sunday for 4 weeks she paints her nails with a different brand of polish and records how many days she lasts before she gets her first chip. she makes sure to use the same bottom coat and top coat with each type of polish, and she makes sure to do the same weekly routine each week so that her nails aren't getting treated more roughly different weeks.

it is a learned trait

explanation:

the answer is c most of the fortnite players usually buy v bucks to get the battle pass and other cosmetics but some players who are referred to as "no skins" don't   buy skins and are usually noobs.

many other transport proteins, often called pumps, move materials against a concentration gradient. active transport drives molecules across a membrane from a region of lower concentration to a region of higher concentration. this process, shown in figure 5.1, uses transport proteins powered by chemi- cal energy.