Gas - A non-renewable resource

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Across
  1. 2. Gas is a non-_______________ source of energy.
  2. 4. The type of resource gas is.
  3. 5. The controversial process of extracting gas that involves injecting bedrock with water and chemicals.
  4. 6. Used to transport gas.
Down
  1. 1. The country with the highest gas reserves.
  2. 2. The process of removing unwanted chemical impurities from gas.
  3. 3. Gas forms from decomposing plant and ________ animal matter, combined with heat and pressure below the surface of the Earth.
  4. 7. The energy the plants originally obtained from the _________ is stored in the gas.