Read this excerpt from "A Student's Guide to Global Climate Change."
You probably know someone with asthma, or maybe
you have this condition yourself. Certain kinds of air
pollutants, like ozone, can make asthma and other
lung conditions worse. Ozone found high in the
atmosphere is called "good ozone" because it protects
life on Earth from the sun's harmful ultraviolet rays.
Ozone can also be found close to the surface of the
Earth, where it is considered "bad ozone" because it's
the main ingredient of smog and is harmful for people
to breathe. Bad ozone is created from pollutants that
go through chemical reactions in the atmosphere.
Climate change is likely to increase the amount of bad
ozone in the air because more ozone is created when
the temperature is warm.
Which best states the author's purpose in writing the
paragraph?
to compare and contrast "good" and "bad" ozone
layers
to inform readers about the negative effects of air
pollution on life
to increase awareness of asthma and other lung
conditions
to list the steps involved in creating a "bad" layer of
ozone