Which gas makes up the greatest percentage of Earth's atmosphere?
A B C D
argon nitrogen nitrous oxide carbon dioxide
Question: Which gas makes up the greatest percentage of Earth's atmosphere?
(A) argon
(B) nitrogen
(C) nitrous oxide
(D) carbon dioxide

Answer: (B) nitrogen
Answer: (C) nitrous oxide
Question: Which gas makes up the greatest percentage of Earth's atmosphere?
(A) argon
(B) nitrogen
(C) nitrous oxide
(D) carbon dioxide
Answer: (B) nitrogen