A) a material medium
B) the atmosphere
C) a field
D) heat

A) a vacuum
B) the high energy of the Sun
C) artificial lights
D) the energy of distant stars

A) energy that moves as EM waves
B) conversion of EM waves into kinetic energy
C) speed of EM waves in a vacuum
D) motion of a medium caused by EM waves

A) always remains constant
B) decreases as the waves spread out
C) increases as the amount of energy increases
D) depends on the source of the waves

A) pass through the water without interacting with it
B) are refracted
C) convert electromagnetic energy into heat
D) are reflected in many directions

A) x-rays
B) ultraviolet light
C) microwaves
D) radio waves

A) radio waves
B) ultraviolet light
C) gamma rays
D) x-rays

A) radio waves
B) ultraviolet light
C) microwaves
D) x-rays

A) ultraviolet light
B) radio waves
C) microwaves
D) infrared light

A) ultraviolet light
B) microwaves
C) visible light
D) radio waves

A) x-rays
B) ultraviolet light
C) radio waves
D) microwaves

A) ultraviolet light
B) x-rays
C) radio waves
D) microwaves