How Long Did It Take for Oxygen to Build Up

question 36

Multiple Choice

How long did it take for oxygen to build up in the Earth's atmosphere to its present levels?

• A) 545 million years
• B) 360 million years
• C) 2 billion years
• D) 3.5 billion years

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Definitions:

Suburbanism

A way of life outside city centers that is organized mainly around the needs of children and involves higher levels of conformity and sociability than life in the central city.

Chicago School

An economic school of thought originating from the University of Chicago, emphasizing free-market principles and the reduction of government intervention in the economy.

Urban Culture

The characteristic way of life of urban populations, including their cultural forms, expressions, and experiences unique to cities.

Urbanism

A way of life that, according to Louis Wirth, involves increased tolerance but also emotional withdrawal and specialized, impersonal, and self-interested interaction.