crossword #1

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Across
  1. 1. the number of the world's continents
  2. 5. the primary source of earth's energy
  3. 7. the process that plants use to convert sunlight into food
  4. 9. animals that eat both plants and meat
  5. 10. an essential gas that enables humans to breathe
Down
  1. 2. the only planet capable of sustaining life
  2. 3. part of the plant that takes in water and minerals from the soil
  3. 4. the biggest planet in the solar system
  4. 6. the first element of the periodic table
  5. 8. the number of planets in the solar system