Which statement is true of President Andrew Jackson? A. He was the first president to run for office twice. B. He was the only president to serve two terms. C. He was the first president to come from a wealthy family. D. He was the first president from the West.

Ascientist performs an experiment where she measures the mass of a piece of metal, pours acid onto the metal, washes the metal, and then re-measures the mass of the metal. the scientist repeats the experiment several times, each time increasing the amount of acid used. the dependent variable in the experiment is the: initial mass of the metal final mass of the metal amount of acid used washing the metal