Science Crossword puzzle

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Across
  1. 3. is the protection and preservation of natural resources
  2. 6. Earth's natural energy resources need to be conserved and used efficiently.
  3. 8. is using scientific principles and knowledge to invent new tools or devices to make our lives easier or solve new problems
Down
  1. 1. is essential for living things.
  2. 2. To successfully manage these natural resources we must conserve resources, increase efficiency, utilize technology
  3. 4. means to do something without wasting time or energy
  4. 5. the invisible gaseous substance surrounding the earth, a mixture mainly of oxygen and nitrogen.
  5. 7. the upper layer of earth in which plants grow, a black or dark brown material typically consisting of a mixture of organic remains, clay, and rock particles.