What is the dominant geographic feature in africa

During the era of european expansion, what was the biggest reason for spain’s push for exploration?

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

Search america's open door policy with china beginning in 1899. explain how relations with the united states and china have changed and the effects of the open door policy on both countries.