Natural resources

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Across
  1. 3. the layer below stratosphere
  2. 5. Nitrogen —> nitrite and nitrate
  3. 6. cycling of matter and transfer of energy
  4. 10. nitrogen gets converted to this when animal dies
  5. 12. used for precipitation
  6. 14. product of photosynthesis
  7. 17. atomic no.6
  8. 18. process that warms earth
  9. 19. home for marine life
  10. 20. fast moving air
Down
  1. 1. process of using oxygen for breaking down food
  2. 2. wonder liquid
  3. 4. NO2
  4. 7. falls down as rain containing sulphuric dioxide and oxides of nitrogen
  5. 8. NO3
  6. 9. a type of greenhouse gas
  7. 11. plants absorb minerals from this
  8. 13. Part of earth not covered in water
  9. 15. atomic no.7
  10. 16. Collectively plants, animals and landscapes