Homework #20

18. a. Reusing is the use of the same item multiple times for the same, or different tasks the item is applicable to. Recycling is when an item is reprocessed into a a different item made of parts, or all of the same substances. 
      b. Reusing: water bottles. Recycling: Cans. 

19. a. Soil, water, plants, animals. 

      b. Petroleum, copper, natural gas, coal. 

20. a. reusing. 

      b. recycling.
      c. reusing. 

21. Both glass from a light bulb and paper from a newspaper can be recycled. In fact, since paper that is not recycled leaves a high proportion of combustibles as waste, the newspaper can be sent to a waste-to-energy plant to produce energy that can be used to power the light bulb.