Earth's average temperature has risen by how much in the past 100 years?
A) 0.5F
B) 1.5F
C) 2.5F
D) 3.5F
Question 2
The ozone layer is
A) close to Earth and poses no serious health threats.
B) in the stratosphere and protects the planet from UVB radiation.
C) a harmful chemical that is produced when oxygen interacts with water.
D) a layer of toxic gas produced by the discharge of aerosols, refrigerants, and solvents high into the earth's stratosphere.