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Home Q & A Board Science-Related Homework Help Physics Astronomy
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rachel3430 rachel3430
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5 years ago
The figure above shows the geological times scale. The Earth's atmosphere has been oxygen rich for
A) about 2 billion years.      B) about 500 million years.
C) a few million years.      D) its entire history.
Textbook 
The Essential Cosmic Perspective

The Essential Cosmic Perspective


Edition: 7th
Authors:
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samanthajones10samanthajones10
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5 years ago
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rachel3430 Author
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5 years ago
Thank you, thank you, thank you!
wyq2651
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Yesterday
This helped my grade so much Perfect
DaiwalkerX
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2 hours ago
Helped a lot
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