I'm stuck on two questions 1) the harappans used to build their cities? 2) which major river flows through the northern and northeastern regions india? keep in mind that this river has played a huge role in the development of indian civilization. river flows through the northern and northeastern regions of india?

clay or mud

Ganges

Explanation:

The Harappan civilization was an ancient culture also known as the Indus Valley Civilization. This civilization flourished during the Bronze Age, from 3300 BCE to 1300 BCE. The civilization extended from northeast Afghanistan through Pakistan and into western and northwestern India.The Ganges river is a river that flows through India and Bangladesh. The river has enormous cultural and social importance in this region. It starts in the western Himalayas and empties into the Bay of Bengal. The Ganges river is also one of the most polluted rivers in the world, mainly due to the large number of people that live by it.