The transfer of plants, animals, people, and diseases between hemispheres. This would be the correct answer!!!
Because they had all they needed where they where at
True I think look in your textbook
Answer:
Explanation: Although there were many geographic features near the Plateau Tribes, perhaps the most important one was the Columbia River, which provided large amounts of salmon and eel for the tribes.The area also is surrounded by the Cascade Mountains, and Sierra Nevada Mountains on the west, and part of the Rocky Mountains on the east side, and the Columbia Plateau. Over forty seven tribes lived in this area.
