Water:- Water makes up 70% of earth’s surface but more than 97% of that is too salty for drinking or irrigation.Of the usable 3% water more than 75% is frozen as ice caps and glaciers.
This leaves less than 0.5% that is available
(as groundwater aquifers, rivers, lakes and streams) for human consumption.
2009-12-22
good,and very useful
as an aspirent for civil serveses it is very very impartant to me
extremely useful