求用英语写的水循环过程和种树的过程。（作文）

Alltheoceansoneartharesalty,whileinlandwateristypicallyfresh.Howdoeswaterbecomesalty?We'llansweralistener'squestion--todayonEarthandSky.

DB:ThisisEarthandSky.WerecentlyvisitedtheAustinChildren'sMuseuminTexastorecordyoursciencequestions.ThisoneisfromJeanaLungwitz.

JeanaLungwitz:Whyaretheoceanssaltwaterandtheriversandlakestypicallyfreshwater?

JB:Jeana,firstimagineateakettle.Ifyouboiltapwatertomaketea,someofitevaporates.Afterawhile,youmightnoticeahardcrustofmineraldepositsformsonthebottomofyourteapot

DB:Thatcrustistherebecausewhentapwaterevaporatesitleavesbehindanydissolvedsaltsandminerals.Nowtakethisscenariototheocean.MostwateronEarthevaporatesfromthesurfaceoftheocean.Thereitleavesbehinddissolvedsalts.Then,whenwaterprecipitatesoutoftheatmosphere,itfallsasfreshwater.

JB:Thefreshwaterthatfallsontolandcascadesoversurfaceslikerocksandsediments.Hereitpicksupnutrients,chemicals,andsalts.Thewatercarriesthedissolvedsaltsonitslongjourneybacktosea.Ifyourunthiswatercycleoverandoveragain,throughfourandahalfbillionyears,youeventuallyleavealotofsaltintheocean.

DB:Infact,ifyoucamebackinanotherbillionyears,theoceanwouldbeevensaltierthanitisnow.ThanksforyourquestionJeana.AndwiththankstotheNationalScienceFoundation,we'reBlockandByrdforEarthandSky.