SSC MTS EXAM

Detailed explanation-1: -Ob River, river of central Russia. One of the greatest rivers of Asia, the Ob flows north and west across western Siberia in a twisting diagonal from its sources in the Altai Mountains to its outlet through the Gulf of Ob into the Kara Sea of the Arctic Ocean.

Detailed explanation-2: -Since the three great Siberian rivers, the Ob, the Yenisey, and the Lena all flow into the Arctic Ocean, the aim was to find parts or branches of these rivers that flow approximately east-west and find short portages between them. Since Siberia is relatively flat, portages were usually short.