Which of the following statements about ozone are true? what are the two correct answers.
1. Ozone in the upper atmosphere protects Earth from the sun's rays.
2. Ozone is helpful for reducing smog levels.
3. Ozone at ground level is harmful to human health.
4. Most ground level ozone is released by vehicles.
5. Trees and plants help to decrease levels of ozone in the atmosphere.
The two correct statements are:
1. Ozone in the upper atmosphere protects Earth from the sun's rays.
3. Ozone at ground level is harmful to human health.