The main factor was the utilization of raised field agriculture. They would build these fields that had been artificially raised to a certain height along a flowing water source (mostly rivers but occasionally streams as well in some cases). When tropical weather patterns would cause said water sources to flood, instead of washing away the crops, it would act as irrigation for the raised fields. Securing a steady food source allowed the Mayans to support a large civilization in the tropical regions they called home.
Answer:
The Good Neighbor Policy was the foreign policy that was led by President Franklin Roosevelt and his administration regarding the countries of Latin America. The United States wanted to have good relations with its neighbors, especially at a time when conflicts were beginning to take hold, and this policy was more or less meant to gather support in Latin America. Through the Good Neighbor Policy, the United States was to keep its eye on Latin America in a more peaceful way than in the past. This in fact ended with unpopular military interventions and switched to other methods to cope with the impacts of Latin America: pan-Americanism, support for strong local tenants, national guard training, economic and cultural interference, export-import bank loans, and monitoring of finance and political subversion.
Mesopotamia's rivers (Tigris and Euphrates) are key to their civilization.
Because of the rivers Sumerians (Mesopotamia's people) could trade and travel through them.
Not to mention just plain drinking water.
Another benefit of the rivers was irrigation.
The awnser for this is that both is B
