What can be inferred about mississippian society from the remains at cahokia? what characteristics did the hopewell and anasazi societies share? how was the origin of civilization in peru similar to that of the river valley civilizations of egypt and mesopotamia? how were the inca rulers able to maintain control over their vast empire? what were three major achievements of maya civilization? why did the aztec sacrifice human beings to their gods? both the aztec and the inca created formidable empires. what weaknesses, if any, did these empires have?