The collapse of mesopotamian society, like the collapse of later civilization, was caused

a constant invasions from foreigners
b a series of famines
c migrations of large groups to other countries
d tension between neighboring city-states

the government paid religious orders to provide basic education to native american children on reservations. in the late 19th and early 20th centuries, the bureau of indian affairs (bia) founded additional boarding schools based on the assimilation model of the off-reservation carlisle indian industrial school.

a.) are both appointed for life