7)
a) what primary processes account for the difference between surface and deep water concentration of n (as nitrate) and p (as phosphate)?
b) what process leads to the the large surface water values of pb (lead) seen in the ocean?

The caste system in india was used for what purpose? a) to ensure that all people had an adequate income b) to prevent the rich from taking too much power c) to provide social control and conformity according to one’s birth d) to draft a military capable of defending india from mongol invasion