Sacred to Hindus, the 1,560-mile (2,510-km) Ganges River in northern India rises from the Gangotri glacier in the Himalayas and empties into the Bay of Bengal after branching into many distributaries. Although the river is highly polluted due to its proximity to major population centers, a rare species of freshwater dolphin and a critically endangered type of shark live in its waters, and its fertile plain supports many crops. About how many people are thought to live in the Ganges basin? Discuss