Which of the following is not true of greenhouse gases?
a.
they absorb earth’s radiation.
b.
they are produced solely by human activities.
c.
they are transparent to incoming solar radiation.
d.
they include carbon dioxide and water vapor.

How have high taxes on tobacco products impacted the number of people who use them? a. the number of tobacco users has increased. b. the number of tobacco users has decreased. c. the number of tobacco users has not changed. d. the number of adolescent tobacco users decreased, while the number of adult users increased