Oxygen (O₂) Is

question 38

Multiple Choice

Oxygen (O₂) is

• A) a gas that principally originates from volcanic sources.
• B) a by-product of plant-leaf operations that are stimulated by light.
• C) one of the gases from Earth's earliest atmospheres.
• D) now measured at 78.084 percent by volume in the homosphere.

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Definitions:

Pastoralist

People or cultures that rely on domesticated animal herding as their primary source of livelihood.

Agricultural

Pertaining to farming or the cultivation of plants and the rearing of animals to provide food, fiber, and other products.

Horticulturalist

An individual or community that practices horticulture, the art or practice of garden cultivation and management.

Idea of Progress

The belief that society can grow and evolve in a positive direction through advancements in science, technology, and social organization.