A) A wood burning stove
B) An automobile that operates on fuel cells
C) A coal burning generator
D) A gasoline burning automobile

A) Heat from within the Earth's crust
B) Running water
C) The sun
D) The moon

A) The number of clouds in the sky
B) The state of the atmosphere at any particular time
C) The amount of moisture in the air
D) The speed of the wind

A) Rotation
B) Magnetic Field
C) Atmosphere
D) Temperature

A) The sun damages life on Earth
B) The sun causes plants to wither and die
C) The sun powers life on Earth
D) The sun protects life on Earth

A) The Earth's rotation
B) The Earth's changing distance from the sun
C) Changes in the sun's intensity
D) The tilt of the Earth on it's axis

A) It reflects light from stars
B) Because it reflects sunlight
C) It makes it's own light
D) It reflects light from Earth

A) Deep craters
B) High plateaus
C) Sunken plains, or seas
D) Mountains

A) Electricity
B) Light
C) Motion
D) Heat

A) Lift and thrust
B) Temperature and pressure
C) Wind and rain
D) Motion and time