托福作文模板：Icebergs

最权威的国际教育服务平台资料来源：教育优选托福作文模板：Icebergs范文的题目：IcebergsIcebergsareamongnature’smostspectacularcreations,andyetmostpeoplehaveneverseenone.Avagueairofmysteryenvelopsthem.Theycomeintobeing-----somewhere------infaraway,frigidwaters,amidthunderousnoiseandsplashingturbulence,whichinmostcasesnoonehearsorsees.Theyexistonlyashorttimeandthenslowlywasteawayjustasunnoticed.Objectsofsheerestbeautytheyhavebeencalled.Appearinginanendlessvarietyofshapes,theymaybedazzlinglywhite,ortheymaybeglassyblue,greenorpurple,tintedfaintlyofindarkerhues.Theyaregraceful,stately,inspiring-----incalm,sunlightseas.Buttheyarealsocalledfrighteninganddangerous,andthattheyare----inthenight,inthefog,andinstorms.Eveninclearweatheroneiswisetostayasafedistanceawayfromthem.Mostoftheirbulkishiddenbelowthewater,sotheirunderwaterpartsmayextendoutfarbeyondthevisibletop.Also,theymayrolloverunexpectedly,churningthewatersaroundthem.Icebergsarepartsofglaciersthatbreakoff,driftintothewater,floataboutawhile,andfinallymelt.Icebergsafloattodayaremadeofsnowflakesthathavefallenoverlongagesoftime.Theyembodysnowsthatdrifteddownhundreds,ormanythousands,orinsomecasesmaybeamillionyearsago.Thesnowsfellinpolarregionsandoncoldmountains,wheretheymeltedonlyalittleornotatall,andsocollectedtogreatdepthsovertheyearsandcenturies.Aseachyear’ssnowaccumulationlayonthesurface,evaporationandmeltingcausedthesnowflakesslowlytolosetheirfeatherypointsandbecometinygrainsofice.Whennewsnowfellontopoftheold,ittooturnedtoicygrains.Soblanketsofsnowandicegrainsmountedlayeruponlayerandwereofsuchgreatthicknessthattheweightoftheupperlayerscompressedthelowerones.Withtimeandpressurefromabove,themanysmallicegrainsjoinedandchangedtolargercrystals,andeventuallythedeepercrystalsmergedintoasolidmassofice.