Which term refers to regions of dense forestation, most of which circle the globe near to the equator?
a. tropical swamps
b. bayous
c. rain forests
d. bogs
Question 2
Research shows that improvement in U.S. air quality over the last several decades has resulted in
a. no change in the amount of acid rain.
b. adding about half a year to the typical lifespan.
c. more and more children exercising outdoors.
d. no change in patterns of human health.