Head Sources in the Environment

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Across
  1. 4. gases,
  2. 7. energy resource,
  3. 10. energy sources, friction.
  4. 12. solar heating,
Down
  1. 1. fuels,
  2. 2. effect,
  3. 3. warming,
  4. 5. energy,
  5. 6. energy source,
  6. 8. solar energy systems,
  7. 9. energy source,
  8. 11. energy balance,