What type of a map shows population density? How do you know that Cairo has more people in it than El Giza or Alexandria?

What kind os source would a historian use to get a firsthand account of a past event

Explain how agriculture and textile factories impacted the economic development of south carolina (4 points)

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