Clean and Energy

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Across
  1. 2. Microorganisms that cause disease
  2. 4. A type of energy produced through currents that led to the replacement of gas lamps.
  3. 6. The process foods like milk go through to become safe to eat.
  4. 7. A heat engine that performs work using steam as fuel
Down
  1. 1. A system added to cities in order to help wuth hygiene and waste disposal
  2. 3. The idea that some diseases are caused by microrganisms and bacteria
  3. 5. A black rock burnt for fuel.
  4. 7. A curved pipe that was used to make the first flushing toilet.