Argon
Water Vapor
Carbon Dioxide
methane
The capital of denmark is copenhagen :)
Why might a post classical civilization want to conquer Mesopotamia? It's fertile land provided the foundation for the first human civilizations and its access to the Persian Gulf and location between Europe, Asia, and Africa made it a center of trade.
Answer:
The uppermost layer of earth is the Crust and it is about 30-50 km deep i believe
Explanation:
Learned this last year in Geography for 9th grade
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The build-up of three oxygen created our ozone layer around two billion years ago.
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- The ozone layer is a part of the stratosphere which is located right after the troposphere in the atmosphere of the Earth.
- The ozone gas is made up of the abundance of three oxygen molecules combining with the ultraviolet radiation emitted by the Sun.
- The development of the ozone layer happened around two billion years ago when the oxygen concentration levels on the planet began to rise slowly and gradually.