How were large amounts of oxygen first introduced into earth's atmosphere?

a. they were deposited by comets that collided with earth.

b. they were released from the earth by erupting geysers.

c. they were produced as a byproduct of photosynthesis.

d. they were produced through atmospheric precipitation.

Question

Guest

17 September, 00:19

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Answers (2)

Know the Answer?

Russell Lyons · Answer 1

c. they were produced as a byproduct of photosynthesis.

Mikayla Hernandez · Answer 2

C. They were produced as a byproduct of photosynthesis.