Final answer:
A divide determines the direction a river flows, with the notable example being the continental divide in North America, which directs rivers either towards the Atlantic or Pacific Oceans.
Step-by-step explanation:
True, a divide does indeed determine the direction a river flows. In North America, the continental divide, which is the line of the highest points on the continent, marks the separation between rivers that flow eastward and those that flow westward. This divide is crucial in defining the river basins and the ultimate destinations of the rivers' flows.
For example, a divide can force rivers to the east and lead them towards the Atlantic Ocean, while those on the opposite side might flow west to the Pacific Ocean. Moreover, as a river moves away from its source, the channel widens, the current slows down, and sedimentation increases. Factors such as river velocity and the landscape's shape influence a river's path and the patterns of sediment deposition within it.