A First Rapid Increase of Oxygen in the Atmosphere (The

question 33

Multiple Choice

A first rapid increase of oxygen in the atmosphere (the First Great Oxidation Event) occurred about ____ years ago.

• A) 4.4 billion
• B) 2.4 billion
• C) 1 billion
• D) 600 million

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Definitions:

Public Busses

Describes a common mode of transportation operated on set routes for the general public.

Open Spaces

Areas of land that are not built upon, kept for either environmental purposes, recreation, or urban planning to provide light and space.

Orbitofrontal Cortex

A prefrontal cortex region in the brain involved in the cognitive processing of decision-making.

Obsessive-Compulsive Disorder

A chronic and long-lasting disorder where a person has uncontrollable, reoccurring thoughts (obsessions) and behaviors (compulsions) that he or she feels the urge to repeat over and over.