What has increased in the air dramatically over the last decade?
oil sugar coal Cars H2O CO 2 He O2
A B C D E F G H
CO 2 is carbon dioxide.
CO 2 concentrations in the air have increased over the last decade dramatically
What has increased in the air dramatically over the last decade? (A) oil (B) sugar (C) coal (D) Cars (E) H2O (F) CO 2 (G) He (H) O2