Greenhouse gases include all of the following except ____. a. ...

[altibaby]

Greenhouse gases include all of the following except ____.
   a. argon
   b. methane
   c. nitrogen oxides
   d. carbon dioxide
   e. hydrofluorocarbons

Question 2

How are tree rings used as proxy data to provide an indirect record of past climate conditions?
   a. Tree rings are thicker and the wood is denser when growing conditions are better.
   b. Tree rings are thicker and the wood is lighter when growing conditions are better.
   c. Tree rings are thinner and the wood is denser when growing conditions are better.
   d. Tree rings are thinner and the wood is lighter when growing conditions are better.
   e. Because of variable moisture levels, tree rings cannot be used as proxy data.

[smrerig]

Answer to Question 1

ANSWER: a

Answer to Question 2

ANSWER: a