sentence: Cities have different groups.
sentences_before: Since irrigation gave Ur abundant crops, not everybody needed to work on farms. People learned other skills. Sir Leonard Woolley found a tablet that listed Ur's special workers. The chisel workers made sculptures, the gem cutters made gems, and the fullers stomped on woven wools to make them soft. The metal workers made weapons.
sentences_after: Some of the richer people are more powerful.
concept_name: city
headings: Ur Social classes
categories: Mesopotamia