Water is a chemical substance that is composed of hydrogen and oxygen and is vital for all known forms of life.[1]
In typical usage, water refers only to its liquid form or state, but the substance also has a solid state, ice, and a gaseous state, water vapor or steam. Water covers 71% of the Earth's surface.[2] On Earth, it is found mostly in oceans and other large water bodies, with 1.6% of water below ground in aquifers and 0.001% in the air as vapor, clouds (formed of solid and liquid water particles suspended in air), and precipitation.[3] Oceans hold 97% of surface water, glaciers and polar ice caps 2.4%, and other land surface water such as rivers, lakes and ponds 0.6%. A very small amount of the Earth's water is contained within biological bodies and manufactured products.
Water on Earth moves continually through a cycle of evaporation or transpiration (evapotranspiration), precipitation, and runoff, usually reaching the sea. Over land, evaporation and transpiration contribute to the precipitation over land.
Clean, fresh drinking water is essential to human and other lifeforms. Access to safe drinking water has improved steadily and substantially over the last decades in almost every part of the world.[4][5] There is a clear correlation between access to safe water and GDP per capita.[6] However, some observers have estimated that by 2025 more than half of the world population will be facing water-based vulnerability.[7] A recent report (November 2009) suggests that by 2030, in some developing regions of the world, water demand will exceed supply by 50%.[8] Water plays an important role in the world economy, as it functions as a solvent for a wide variety of chemical substances and facilitates industrial cooling and transportation. Approximately 70% of freshwater is consumed by agriculture.[9]
domingo, 11 de abril de 2010
water rap or song
we need to safe
he need to live
is the water
the condition to live
its mandatory
to safe them
not to waste them
its dieing, is saying
!stop, stop, stop!
you are wrong
you are killing using
cars, bus that are
like missils and swords
its important
but is afected
by the human
and the wastes
he need to live
is the water
the condition to live
its mandatory
to safe them
not to waste them
its dieing, is saying
!stop, stop, stop!
you are wrong
you are killing using
cars, bus that are
like missils and swords
its important
but is afected
by the human
and the wastes
miércoles, 17 de febrero de 2010
biography

Abraham Lincoln (February 12 of 1809 to 15April 1865) was the 16th (1861-1865) President of theUnited States, and the first to be by the GOP.He is remembered for restoring the federal unity of the nationby defeating the Confederate States of America and to endslavery in the United States. However, therights advocates from several states continue to seeLincoln as a tyrant who suspended civil libertiesand eliminated "legitimate right" to secede.
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