project puzzle

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Across
  1. 4. ice
  2. 5. dry ice
  3. 6. carbon dry ice
  4. 7. water
  5. 9. water turn into ice at a low temp of 0
Down
  1. 1. something foggy
  2. 2. of boiling water
  3. 3. frost
  4. 8. hot water