1) This type of precipitation is caused by pollution and is harmful to plants, animals, bodies of water, and buildings.
        A)  Earth
        B)  pollution
        C)  acid rain
        D)  renewable

2) This is another term for global warming.
        A)  erosion
        B)  watt
        C)  Ozone layer
        D)  greenhouse effect

3) The place or type of environment where an animal or plant naturally lives or grows.
        A)  trash
        B)  erosion
        C)  fuel
        D)  habitat

4) A metal container.
        A)  pollution
        B)  soil
        C)  greenhouse effect
        D)  can

5) This covers most of the earth's land, and is made up mostly of disintegrated rocks.
        A)  fuel
        B)  soil
        C)  pollution
        D)  trash

6) We must breathe this gas in the air to survive.
        A)  oxygen
        B)  fuel
        C)  air
        D)  ocean

7) A plant with leaves, roots, and a single, woody trunk.
        A)  tree
        B)  coal
        C)  soil
        D)  hydroelectricity

8) Manufacturing companies and other businesses.
        A)  rainforest
        B)  habitat
        C)  industry
        D)  renewable

9) The invisible mixture of gases we breathe.
        A)  Earth
        B)  air
        C)  rainforest
        D)  water cycle

10) To remove dirt or stains from something.
        A)  gasoline
        B)  litter
        C)  soil
        D)  clean

11) A unit of electric power, equal to one joule of work per second.
        A)  watt
        B)  hydroelectricity
        C)  fluorescent
        D)  water cycle

12) A type of fuel used in cars with internal-combustion engines. This is made from petroleum.
        A)  gasoline
        B)  erosion
        C)  conservation
        D)  hydroelectricity

13) A type of potential energy that can be burned to supply heat, such as wood.
        A)  fuel
        B)  ocean
        C)  fluorescent
        D)  water cycle

14) This occurs when running water, sea waves, wind, or glaciers pick up and carry away materials from the earth's surface.
        A)  tree
        B)  erosion
        C)  electricity
        D)  air

15) Harmful substances that are released and make our planet dirty, noisy, or unhealthy.
        A)  pollution
        B)  clean
        C)  conservation
        D)  hazardous