Early Civilizations Crossword

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Across
  1. 1. Mesopotamian civilization that invented the 60 minute hour
  2. 3. American civilization that did all their building with no metal tools
  3. 5. this river valley civilization in India had great plumbing and no warfare
Down
  1. 2. African civilization discovered moldy bread could prevent infections
  2. 4. Asian civilization that invented the plow and wheelbarrow