Question 1
The most extreme example of the greenhouse effect in the solar system is associated with an abundance of carbon dioxide in the atmosphere of ________.
◦ Earth
◦ Mars
◦ Mercury
◦ Venus
Question 2
The polar caps on ________ are thought to be mainly water ice with a thin layer of carbon dioxide in the cold season.
◦ Earth
◦ Mars
◦ Mercury
◦ Venus