How much of the Earth's atmosphere do scientists believe was made of oxygen 2.3 billion years ago?

A.) 70%

B.) 22%

C.) 1%

D.) 10%

Question

Jonathon Hogan

27 December, 08:39

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Answers (1)

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Highbeam · Answer 1

A because without o2 there would be no fish snakes dinos and all kinds of other living things.

How much of the Earth's atmosphere do scientists believe was made of oxygen 2.3 billion years ago?A.) 70%B.) 22%C.) 1%D.) 10%