Question

when the oxygen came to earth
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Answer 1

Explanation:

The ability to generate oxygen via photosynthesis likely first appeared in the ancestors of cyanobacteria. These organisms evolved at least 2.45–2.32 billion years ago, and probably as early as 2.7 billion years ago or earlier.

Answer 2

Answer:

Oxygen came on earth when the earth had a normal temperature and the trees started growing

Explanation:

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