Answer: the Neolithic period
Explanation:
A period in history in which humans transitioned from hunting and gathering food to the farming of plants and animals is called the Neolithic period. People were starting to become farmers and their life got more settled.
This transition is also known as the Neolithic Revolution or the Agricultural Revolution.
Easy. Answer is oxygen because it says which one was missing before any life was on earth. And in order to have life on earth you need oxygen!
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The lion population will decrease because their prey is being hunted
I believe your answer would be B forgive me if im wrong