Global warming is caused mainly by a. greenhouse gases that ...

[ETearle]

Global warming is caused mainly by
 
  a. greenhouse gases that accumulate in the atmosphere.
 b. changes in the earth's orbit around the sun.
 c. increases in the use of solar energy.
 d. the collective body heat given off by increasing populations.

Question 2

All of the fish have died in one-third of the lakes in New York's Adirondack Mountains due to
 
  a. acid rain.
 b. global warming.
 c. destruction of the ozone layer.
 d. overfishing.

[juicepod]

Answer to Question 1

a

Answer to Question 2

a