The river is a large stream of water. The river rises generally from a mountain or lake. At first several very narrow streams of water join together and form one larger stream. This stream gradually widens in its course. On its way, it is joined by other smaller rivers. They are called its tributaries. At last the river falls into a sea, lake or another river. The mouth of the river becomes very wide. A river generally receives its water by the melting of snow on mountains. Sometimes it is fed by rain. The river is of great use to us. It flows through many places. It makes them fertile. Prosperous cities are all situated on the banks of rivers. The river is of great help to farmers. Crops grow there in plenty. Irrigation is possible easily where there is a river. Irrigation helps agriculture. The places by the side of a river are generally healthy. The river supplies us with drinking water. The water-works of the municipalities generally get their supply of water from rivers. Bathing in the river improves our health. Yet rivers sometimes do us great harm. During the rainy season, some rivers wash away their banks. Many people are thereby rendered homeless and helpless. This causes a great loss to the country. It is true that rivers sometimes do us great harm. Still a river is a blessing to us. It helps us in many ways. So it is the duty of the Government to see that the rivers are not dried up. Dams have been made there to store the water of these rivers. It prevents flood and helps agriculture and the generation of electricity.