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

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

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

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

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

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

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

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

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

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