How did civilizations that were far from rivers support agriculture, and how did this affect their development? a. they built canals to bring water to crops, which gave them a surplus to support a growing civilization. b. they traded for water to support their crops, which gave their civilization a chance to survive. c. they conquered other civilizations that were next to rivers, which gave them a new location to thrive. d. they relied on water from neighboring civilizations, which in forming trade agreements.