The Great Oxygen Event Marks the Time, Approximately 2

question 103

Multiple Choice

The Great Oxygen Event marks the time, approximately 2.5 billion years ago, when ______ .

• A) there was enough oxygen in the atmosphere to support a major burst of life on Earth
• B) there was a massive volcanic eruption that lead to a very rapid increase in oxygen levels on Earth
• C) there was significant oxygen in the atmosphere
• D) there was a cataclysmic weather event that absorbed most of the oxygen in the atmosphere and locked it into iron deposits in the oceans
• E) photosynthesis was clearly established and producing oxygen

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Definitions:

Opening

The initial part or phase of something, such as an event, book, or business opportunity.

Document

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Revising

The process of reviewing and altering content in a text to improve clarity, coherence, and overall quality.

Quality

The degree to which something meets certain standards or fulfills requirements, expectations, or specifications.