请阅读短文,完成此题。 Whenweanalyzethesaltsalinity(盐溶度)ofoceanwaters,wefindthatitvariesonlyslightlyfromplacetoplace.Nevertheless,someofthesesmallchangesareimportant.Therearethreebasicprocessesthatcauseachangeinoceanicsalinity.Oneoftheseisthesubtractionofwaterfromtheoceanbymeansofevaporation.Inthismanner,thesalinityisincreased,sincethesaltstaysbehind.Ifthisiscarriedtotheextreme,ofcourse,whitesaltwouldbeleftbehind;this,bytheway,ishowmuchofthetablesaltweuseisactuallyobtained. Theoppositeofevaporationisprecipitation,suchasrain,bywhichwaterisaddedtotheocean.Heretheoceanisbeingdilutedsothatthesalinityisdecreased.Thismayoccurinareasof highrainfallorincoastalregionswhereriversflowintotheocean.Thussalinitymaybeincreasedbythesubtractionofwaterby-evaporation,ordecreasedbytheadditionoffreshwaterbyprecipitation. Normally,inhotregionswherethesunisverystrong,theoceansalinityissomewhathigherthanitisinotherpartsoftheworldwherethereisnotasmuchevaporation.Similarly,incoastalregionswhereriversdilutethesea,salinityissomewhatlowerthaninotheroceanicareas. Athirdprocessbywhichsalinitymaybealteredisassociatedwiththeformationandmeltingofseaice.Whenseawaterisfrozen,thedissolvedmaterialsareleftbehind.Inthismanner,seawaterdirectlybeneathfreshlyformedseaicehasahighersalinitythanitdidbeforetheiceappeared.Ofcourse,whenthisicemelts,itwilltendtodecreasethesalinityofthesurroundingwater. IntheWeddellSea,thedensestwaterintheoceanisformedasaresultofthisfreezingprocess,whichincreasesthesalinityofcoldwater.Thisheavywatersinksandisfoundinthedeeperportionoftheoceansoftheworld. WhichofthefollowingstatementsisTRUEaccordingtothepassage? 查看材料
A.Oceanic salinity has great effect on sea life.
B.Many factors combine to cause changes in oceanic salinity.
C.The movement of the water is related to the amount of salt.
D.The temperature of the water has much to do with the oceanic salinity.
正确答案是D