Why do people talk about what already happened in the past, like history, and not what's going to happen?

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

How did people in the 14th century understand black death

What were some of the ideas that the democratic party emphasized that allowed them to appeal to most white voters?