This is beacuse people find sources of food or a new resource
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Ravenna was important in history as the capital of the Western Roman Empire in the 5th century ad and later (6th–8th century) of Ostrogothic and Byzantine Italy.
Explanation:
It came under Roman control in 191 bc and soon became important because it possessed one of the few good port sites on the northeastern coast of Italy.
The treaty added an additional 525,000 square miles to United States territory, including the land that makes up all or parts of present-day Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. Mexico also gave up all claims to Texas and recognized the Rio Grande as America's southern boundary.
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B: "...enabled modern humans to travel further north..."
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