Why would a sumerian make offerings or sacrifices to their gods

Sumerians believed that not only were there high gods but also personal Gods that relayed the prayer to the high Gods. Every head of a house prayed to their God would intercede for them and their family and in exchange, they offered prayer, supplications and sacrifice while still worshiping other gods in the pantheon.

answer; /// the correct answer is evidence of the olmec civilization has been found in southern american in a hot steamy forest, archaeologists have found earthen artifacts at several sites that were evidence of the olmec civilization. these   artifacts were mounds,courtyards and pyramids build of stones, also on top of the mounds were many monuments made of stone, some of these stone structures are very large, they weigh as much as 44