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

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

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

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

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

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

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

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

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

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