How did the expansion of railroads affect American Indians in the West? They were displaced from their tribal lands.
They moved into towns with the new settlers.
They stopped farming and took railroad jobs.
They were forced to move to New England.

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