Answer: Desertification and soil erosion.
Buildup of armaments in preparation for war
<span>The “urban revolution” or the leap into civilization was made about 3500BC; over the next 3,000 years, civilization spread throughout the ancient Near East. The peoples of the ancient Near East learned to master their environment and create a food surplus. These ancient peoples “invented” civilization and developed early forms of government, law, society, and economies. These peoples created notable works of art and architecture, from the Ziggurat to the Pyramids to the palaces of Minoan civilization. They invented writing: cuneiform and hieroglyphics. They created sophisticated regions, ranging from the polytheism of most peoples to the ethical monotheism of the Hebrews. As it did so, great empires rose and fell, creating a pattern that will be imitated throughout history; most peoples, when given the opportunity, become aggressive and expansionist and build empires; each empire is then destroyed by the ambitions of the people who built it. Surviving the collapse of Empires was the culture created by these peoples--and it will have an impact on our next cluster of civilizations, the Hellenic, the Hellenistic, and the Roman. Collectively called Classical Civilization, these three dominated the Mediterranean world from ca 500 BC to AD 500.
Hope this helps ;D</span>
C. Transportation
All these systems allow for faster travel of good and more efficient movement of people.
