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

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

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

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

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

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

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

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

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

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