Description : The main source of usable water on the Earth is – (1) Oceans (2) Rivers (3) Underground water (4) Precipitation
Last Answer : (3) Underground water Explanation: Even though most of the Earth's surface is water, only 1% of it is fresh usable water. Ninety-seven percent of the Earth's water is saltwater, which contains too many ... cent of water, followed by Freshwater Lakes: 0.009 per cent; and rivers: 0.0001 per cent.