Why is the ozone layer so important?
A:Because it traps most of the sun's heat
B:Because it blocks harmful ultraviolet rays
C:Because it allows ultraviolet rays to warm the stratosphere
D:Because it contains most of the Earth's oxygen
A:Because it traps most of the sun's heat
B:Because it blocks harmful ultraviolet rays
C:Because it allows ultraviolet rays to warm the stratosphere
D:Because it contains most of the Earth's oxygen