一

　　Water

　　Waterisveryimportantforlivingthings.Withoutwatertherecanbenolifeonearth.Allanimalsandplantsneedwater.Manalsoneedswater.

　　Waterisfoundatmosteverywhere.Eveninthedriestpartoftheworldthereissomewaterintheair.

　　Asweallhavefoundout,watermaybeasolid,oraliquidoragas.Whenitisasolid,itmaybeashardasbrick,Whenitisaliquid,youcanpouritoutofacontainer.Whenitisagas,youcannotseeorfeelit.

　　Althoughabout70percentoftheearth'ssurfaceiscoveredwithwater,therearemanyplacesintheworldstillrunningoutofwater.Soweshouldmakegooduseofwateronearth.

　　水

　　水对生物很重要,没有水,地球上就没有生命.所有的动植物都需要水.人类也需要水.

　　水几乎无处不在.即使在世界上最干燥的地方,空气中也有水.

　　水,正如你所了解的,有固态、液态和气态.当它是固态时,它可以像砖一样硬；当它是液态时,你可以将它从容器中倒出；当它是气态时,你看不见或感觉不到它.

　　虽然地球表面70％是水覆盖着,世界上仍有许多地方缺水.所以我们要好好利用地球上的水.

　　二

　　Waterisacommonchemicalsubstancethatisessentialforthesurvivalofallknownformsoflife.Intypicalusage,waterrefersonlytoitsliquidformorstate,butthesubstancealsohasasolidstate,ice,andagaseousstate,watervapororsteam.About1.460petatonnes(Pt)(1021kilograms)ofwatercovers71%oftheEarth'ssurface,mostlyinoceansandotherlargewaterbodies,with1.6%ofwaterbelowgroundinaquifersand0.001%intheairasvapor,clouds(formedofsolidandliquidwaterparticlessuspendedinair),andprecipitation.Saltwateroceanshold97%ofsurfacewater,glaciersandpolaricecaps2.4%,andotherlandsurfacewatersuchasrivers,lakesandponds0.6%.SomeoftheEarth'swateriscontainedwithinwatertowers,biologicalbodies,manufacturedproducts,andfoodstores.Otherwateristrappedinicecaps,glaciers,aquifers,orinlakes,sometimesprovidingfreshwaterforlifeonland.