英语部分专项练习(一)PartIReadingComprehensionDirections:Thereare4readingpassagesinthispart
Eachpassageisfollowedbysomequestionsorunfinishedstatements
ForeachofthemtherearefourchoicesmarkedA
YoushoulddecideonthebestchoiceandmarkthecorrespondingletterontheAnswerSheetwithasinglelinethroughthecenter
Questions1to5arebasedonthefollowingpassage:Ifthesalinityofoceanwaterisanalyzed,itisfoundtovaryonlyslightlyfromplacetoplace
Nevertheless,someofthesesmallchangesareimportant
Therearethreebasicprocessesthatcauseachangeinoceanicsalinity
Oneoftheseisthesubtractionofwaterfromtheoceanbymeansofevaporation—conversionofliquidwatertowatervapor
Inthismanner,thesalinityisincreased,sincethesaltsstaybehind
Ifthisiscarriedtotheextreme,ofcourse,whitecrystalsofsaltwouldbeleftbehind;this,bytheway,ishowmuchofthetabl