ExerciseI

1。Filleachofthenumberedblanksinthefollowingpassagewithonesuitableword。

Fromthebeginning，waterhasfurnishedmanwithasourceoffoodandahighwaytotravelupon。Thefirstcivilisationsarose____________waterwasadominantelementintheenvironment，achallenge__________man‘singenuity。TheEgyptiansinventedthe365___________calendarinresponse___________theNile‘sannualflooding。TheBabylonians，whowereamong___________mostfamouslaw－makers___________antiquity，devisededictsregulatingwaterusage。WaterinspiredtheChinese___________builda1，000milecanal，acomplexsystem___________，afternearly2，500years，___________stillpartlyinuseandstillcommandstheaweofengineers。Buttheancientsneverfoundcompletesolutions____________theirwaterproblems。TheHwangHo，orYellowRiver，isalsoknown___________“China‘sSorrow“;itissoerraticanddangerous___________inasinglefloodithascausedamilliondeaths。FloodsharassedthegreatcivilisationoftheIndusRivervalley，andinadequatedrainageruinedmuch__________itsland。Today____________dominatesmanasitalwayshas___________。Itspresencecontinuestogovernthelocationofhishomesandcities;itstempestuousvariabilitycankill___________orhisherdsorhiscrops;itsrouteslinkhimto____________fellows;itsimmensevaluemayadd___________alreadydangerouspoliticalconflicts。Therearemanyexamples__________thisinour___________time。