Explanation:
Two lane roads may have "no passing zones" mark by solid yellow line.
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In the suggest period between 200,000 and 12,000 years ago, humans were living a nomadic lifestyle. The humans of this period were hunter-gatherers, and they were constantly moving from one place to another in accordance to the food supply and climate conditions. Because of this constant movement and constant search for better hunting grounds and places where there's much bigger and more constant supply of fruits, vegetables, root plants, they managed to disperse in very big space and little by little to colonize the planet. In this period the cultivation of plants was still not taking place, and also the humans still hadn't managed to domesticate any wild animals, apart from the wolf which gave rise to the dog, but it was used for hunting, not as a food source.
Escape velocity, stillness is possible
1 and 3 are correct, this is due to the fact that modern technology is constantly growing and other developed nations are feeling threatened or inferior when another developed nation grows further ahead. National security has also grown global, just the threat of a foreign country developing nuclear capability is enough for another country to launch missle strikes or other acts in order to quell the threat of another nuclear capable country. 2 is not correct because industrial strategies are being shared throughout the world constantly and the safety of a country no longer stands by their standing army or navy, but by the threat of nuclear capability or a possibility of retaliation through explosive nature. Even today, most wars are done through the army holding down a line, and the navy/airforce launching long ranged missile attacks of various nature.