Name the population you want to study, for instance, "all people aged 18 – 22 in the United States" or "all professional baseball players in the National League."

All professional ballerinas.

Explanation:

To see how they achieve near perfection from their stretches and exercises to Thier rehearsals and onstage. How they take care of a hectic schedule and deal with the pain that comes with being on pointe up to 8 hours a day.

it provides an alternative energy pathway for the reaction to proceed.

a catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction.

catalysts increase the rate of reaction without being used up. they do this by lowering the activation energy needed. with a catalyst, more collisions result in a reaction, so the rate of reaction increases. different reactions need different catalysts.

a catalyst works by providing an alternative reaction pathway to the reaction product. the rate of the reaction is increased as this alternative route has a lower activation energy than the reaction route not mediated by the catalyst.