Excretory System Crossword Puzzle

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Across
  1. 4. cellular waste (urine)
  2. 6. Tube that carries urine from the bladder to the outside of the body
  3. 7. eliminates waste materials to keep the body cells clean
Down
  1. 1. Tubes that lead from each kidney to the bladder
  2. 2. Main organ of the excretory system
  3. 3. Storage sac for urine
  4. 5. liquid stored in the bladder