高考英语专项练习七选五高考英语专项练习七选五PAGE\*MERGEFORMAT4高考英语专项练习七选五专项练习七选五一根据短文内容，从短文后的选项中选出能填入空白处的最佳选项,选项中有两项为多余选项。Secretcodes(密码）keepmessagesprivate。Banks，companies，andgovernmentagenciesusesecretcodesindoingbusiness,especiallywheninformationissentbycomputer。Peoplehaveusedsecretcodesforthousandsofyears。36Codebreakingneverlags(落后)farbehindcodemaking。Thescienceofcreatingandreadingcodedmessagesiscalledcryptography。Therearethreemaintypesofcryptography.37Forexample,thefirstlettersof“Myelephanteatstoomanyeels”Spelloutthehiddenmessage“Meetme.”38Youmightrepresenteachletterwithanumber,Forexample,Let’snumberthelettersofthealphabet，inorder,from1to26.Ifwesubstituteanumberforeachletter,themessage“Meetme"wouldread“13520135。”Acodeusessymbolstoreplacewords，phrases，orsentences.Toreadthemessageofarealcode,youmusthaveacodebook.39Forexample,”bridge“mightstandfor“meet”and“out”mightstandfor“me。”Themessage“bridgeout”wouldactuallymean“Meetme.”40However，itisalsohardtokeepacodebooksecretforlong.Socodesmustbechangedfrequently。A。Itisveryhardtobreakacodewithoutthecodebook.B.Inanylanguage，somelettersareusedmorethanothers。C。Onlypeoplewhoknowthekeywordcanreadthemessage.D。Aslongastherehavebeencodes，peoplehavetriedtobreakthem。E。Youcanhideamessagebyhavingthefirstlettersofeachwordspellitout.F。Withacodebook,youmightwritedownwordsthatwouldstandforotherwords.G.Anotherwaytohideamessageistousesymbolstostandforspecificlettersofthealphabet。二Agardenthat’sjustrightforyouHaveyouevervisitedagardenthatseemedjustrightforyou，wheretheatmosphereofthegardenappearedtototalmorethanthesum(总和）ofitsparts?36。Butitdoesn’thappenbyaccident.Itstartswithlookinginsideyourselfandunderstandingwhoyouarewithrespecttothenaturalworldandhowyouapproachthegardeningprocess.●___37Somepeoplemaythinkthatagardenisnomorethanplants，flowers，patternsandmassesofcolor。Othersareconcernedaboutusinggardeningmethodsthatrequirelesswaterandfewerfertilizers（肥料）。38。However,thereareanumberofotherreasonsthatmightexplainwhyyouwanttogarden。Oneofthemcomes