The correct answer for the question that is being presented above is this one: "oxygen became available from cyanobacteria." About 1.2 billion years ago, eukaryotic and multicelled organisms evolved because oxygen became available from cyanobacteria.
we cannot survive without oceans.
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What is the 1000 year period after the fall of Rome called?
The 1000 year period after the fall of Rome is called Middle Ages. This is a period where the Odovacor, German prince had sway the power of the Roman army of Italy.
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false, Birthrates are usually higher in less developed countries thats why they are more likely to be over populated
