Oxygen in Earth's Atmosphere Built Up Over Time as a Result

question 34

Multiple Choice

Oxygen in Earth's atmosphere built up over time as a result of ____________.

• A)volcanic outgassing
• B)photosynthesis
• C)limestone formation in the ocean
• D)solar radiation splitting molecules of ozone in the stratosphere

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Definitions:

Allergies

Immune system reactions to a particular substance that is not harmful to most people, often manifested by sneezing, itching, or rashes.

Age of Viability

The stage of fetal development at which a fetus has a significant chance of survival outside the uterus, typically around 24 weeks gestation.

Prematurely

Happening before the normal or expected time.

Fetus

A developing mammal or human from the embryonic stage to birth, after major structures have been outlined.