Earth's First Atmosphere Was Composed of

question 39

Multiple Choice

Earth's first atmosphere was composed of

• A)oxygen,hydrogen,and helium.
• B)hydrogen and helium,with trace amounts of ammonia and methane.
• C)gases from volcanic eruptions.
• D)oxygen,water vapor,carbon dioxide,and methane.

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Definitions:

Attention

The cognitive process of concentrating on one aspect of the environment while ignoring other stimuli.

Sensory Store

The initial process of storing sensory information after it is received, lasting for a very brief period.

Attention

The cognitive process of selectively concentrating on one aspect of the environment while ignoring other things.

Selectively

The act of choosing specific items or data while ignoring others based on certain criteria.