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

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

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

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

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

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

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

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

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

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