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spin [16.1K]
3 years ago
11

Where did the original atmospheric oxygen come from

Geography
1 answer:
faust18 [17]3 years ago
3 0

The correct answer is - cyanobacteria.

The atmospheric oxygen came from the cyanobacteria. These were one of the earliest living organisms on Earth. The cyanobacteria was using photosynthesis in order to create its own food. The photosynthesis process requires sunlight, carbon dioxide, water, and oxygen. The oxygen is mostly released as a waste product from the process of photosynthesis, thus the cyanobacteria were literally releasing oxygen that was ending up into the atmosphere. As more and more cyanobacteria there were across the planet, more and more oxygen they were releasing into the atmosphere, slowly changing the composition of the atmosphere, and setting the basis of it as we know it now.

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respectively

Explanation:

Threshold is the minimum population and range is the maximum distance needed to sustain a good. As such, it'd make sense for buprenorphine treatments (a rare service) to have a low threshold since not too many people will be buying it, but it's still sustainable since it's expensive.

"Medium" is a loose definition so I would say any convenience good or service would be good for this one.

 

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Things like hairdressing aren't worth traveling great distances to receive so they have a small range.

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