How did horses significantly impact the lives of the Plains Indians? a. Horses became a primary food source for the tribes.
b. Horses gave the tribes increased mobility, particularly during buffalo hunts.
C. Horses were used as beasts of burden and promoted agricultural development.
d. Horses contributed to increased economic development in the fur trade.

In a modern democracy all elected officials serve for a certain number of terms then must retire a high school sophomore and a senior citizen may vote at the polls together a united states senator votes on immigration law on behalf of your mother through indirect ballot all democracies have a two chamber system of representation united states citizens live in a direct democracy