2) A solid, hard black mineral that burns and gives off heat.
        A)  habitat
        B)  coal
        C)  gasoline
        D)  industry

3) The apparent rise in the earth's temperature that scientists believe is caused by an increase in the amount of carbon dioxide and other gases in the air.
        A)  global warming
        B)  hazardous
        C)  conservation
        D)  Earth

4) Performing or functioning in the least wasteful manner possible.
        A)  clean
        B)  efficiency
        C)  greenhouse effect
        D)  gasoline

5) This is the third planet from the sun.
        A)  renewable
        B)  Earth
        C)  efficiency
        D)  industry

6) A physical agency caused by the movement of electrons, protons, manifesting itself as attraction, replusion, magnetic, luminous, and heating effects.
        A)  greenhouse effect
        B)  rainforest
        C)  electricity
        D)  hydroelectricity

7) An efficient type of light bulb.
        A)  litter
        B)  global warming
        C)  water cycle
        D)  fluorescent

8) The disappearance of forests due to land development, cultivation, or lumbering.
        A)  can
        B)  Ozone layer
        C)  air
        D)  deforestation

9) The constant recycling and movement of water on Earth. Energy from the sun, plants, or animals causes water to evaporate. The water vapor rises in the atmosphere to form clouds. Rain returns the water from clouds back to the earth's surface.
        A)  tree
        B)  ocean
        C)  pollution
        D)  water cycle

10) The large body of saltwater that covers about 70% of the earth's surface.
        A)  ocean
        B)  watt
        C)  renewable
        D)  hazardous

11) Any useless material that is thrown away.
        A)  habitat
        B)  fuel
        C)  trash
        D)  volunteer

12) A layer in the atmosphere which blocks many of the sun's ultraviolet rays from reaching the earth.
        A)  greenhouse effect
        B)  watt
        C)  Ozone layer
        D)  soil

13) The protection and more efficient use of natural resources.
        A)  erosion
        B)  clean
        C)  conservation
        D)  fluorescent

14) A person who helps or offers to do something without getting paid.
        A)  trash
        B)  volunteer
        C)  global warming
        D)  conservation

15) Thermal energy that travels in waves and can pass through empty space as well as some objects.
        A)  oxygen
        B)  acid rain
        C)  radiation
        D)  pollution

16) Power derived from the fall of water from a higher to a lower level, and extracted by means of waterwheels or hydraulic turbines
        A)  erosion
        B)  hydroelectricity
        C)  industry
        D)  electricity

17) A type of fuel formed from the remains of plants or sea creatures millions of years ago.
        A)  Ozone layer
        B)  erosion
        C)  coal
        D)  fossil fuel

18) To throw garbage on the ground instead of in a garbage can.
        A)  litter
        B)  gasoline
        C)  fluorescent
        D)  ocean

19) Potentially dangerous to human beings or the environment
        A)  water cycle
        B)  soil
        C)  volunteer
        D)  hazardous

20) Fuels that can generate power without being used up.
        A)  renewable
        B)  industry
        C)  erosion
        D)  Ozone layer