Which of the following statements about ozone are true? Select the two correct answers.
A. Ozone in the upper atmosphere protects Earth from the sun's rays.
B. Trees and plants help to decrease levels of ozone in the atmosphere.
C. Most ground level ozone is released by vehicles.
D. Ozone at ground level is harmful to human health.
E. Ozone is helpful for reducing smog levels.
A. Ozone in the upper atmosphere protects Earth from the sun's rays.
D. Ozone at ground level is harmful to human health.