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

17 August, 23:48

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Answers (2)

Know the Answer?

Walls · Answer 1

C. They were produced as a byproduct of photosynthesis.

Carlie Pollard · Answer 2

c. they were produced as a byproduct of photosynthesis.