Was manifest destiny good for america?

Draw conclusions  why might a cause like italian unification successfully draw people of very different backgrounds together?  

The divide and rule policy employed by the english was developed by the

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