What two european unions set the stage for the european union? a. nato and the european exchequer b. the marshall plan and comecon c. the warsaw pact and nafta d. the benelux union and the european community

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