<span>Scientists choose where are units of time began and ended based on major changes in life forms at certain times</span>
Sound wave is a pressure caused by the vibration of something in a medium that transfers anergy, like air.
1) Mapping
2) Tracking
3) Military Purposes
Answer: I think the answer is C
Explanation: It is not B because if they moved closer to all of the resources such as water food and shelter then that wouldn't be a bad thing for them, It is also A not because if they did move away from large factories then that would be technically a good thing so the kids in danger of dangerous things, and it is also not D because if they were to move near the center of a country then they can start their own farms. So therefore my answer is C because if they did this then they wouldn't have very many natural resources to rely on.
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