When did the caste system evolve into a four tiered hierarchy

This map shows the member states of the european union (eu). based on this map, what is the most likely reason the eu was formed? a) to increase trade between european nations b) to protect themselves from foreign enemies c) to begin the process of forming one large nation d) to isolate europe from the rest of the international community j

Name one type of data that h-r diagrams do not show.

The position on the earth in which a place can be found