Multiple Choice
According to the figure shown below, approximately how many years ago did oxygen finally get to half its current abundance in Earth's atmosphere? 
A) 3 billion years ago
B) 1 billion years ago
C) 0.6 billion years ago
D) 0.25 billion years ago
E) 0.1 billion years ago
Correct Answer:
Verified
Correct Answer:
Verified
Related Questions
Q23: _ in our atmosphere is a direct
Q25: If you found absorption rising from _
Q26: Earth's sky is blue because:<br>A) blue light
Q27: The best way to look for life
Q29: Aurorae are produced only near the northern
Q30: The amount of carbon dioxide in the
Q31: Given the thickness and chemical composition of
Q32: The shape of the Earth's magnetosphere is
Q33: Carbon dioxide levels in Earth's atmosphere have
Q78: Earth has roughly _ times more atmospheric