Unit2Sailingtheoceans当今航海技术达到前所未有的水平，那么你知道古代一些有关航海方面的仪器吗？Sinan，theancientChinesecompassItwasinventedbyZhangHengintheHanDynasty.Itismadeupofabronzefoundation(青铜底盘)andmagneticspoon(磁勺)whichismadeofnaturalmagnet，positionedrightinthecenterofthefoundation.Thehandleofthespoonpointstothesouth，whiletheothersidepointstothenorth.WhentheSinanisinthestill，thehandleofthespoonpointstothesouthbecauseoftheinfluenceoftheterrestrialmagnetism(地磁)．AstrolabeIthas17starslistedaswellasamapoftheskyoverhead(for37degrees)andtheecliptic(黄道)．ThetimeofdayornightisontheoutsideedgewithnoonatthetopoftheAstrolabeandmidnightatthebottom.Itcomeswithacarryingchain，apouch，andabookonitsuse.Thereversesidehasasightformeasuringtheelevationsoftheheavenlybodies.SextantThesextantisanavigationalinstrumentformeasuringtheanglebetweenthehorizonandsomeobjectinthesky.Firstasailorlooksatthehorizonthroughaneyepiece.Attheseelightfromthesunorastarreflectedoffasmallmirrorontopoftheinstrument，ontoasecondmirrorandintotheeyepiece.Thenavigatorcanthenseetwoimages，thehorizonandthesunsidebyside.Hecanthenmeasuretheanglebetweenthemonascaleatthebottomoftheinstrument.Thescalegoesfrom0to120degrees.Anearlierinstrument，calledaquadrant，measuredinangleinthesamewaybutitcouldonlymeasureanglesfrom0to90degrees.NauticalchartNauticalchartsaremapsofthedepthoftheseaandthecurrentsoftheoceans.Theyprovidemodernsailorswithroutesthroughtheseas，ratherlikeroadsthroughthecountryside.Theinformationbegantobecollectedinthenineteenthcenturyandhascontinuedtobeupdatedeversince.ThesechartswerenotavailabletoCaptainBlighorZhengHe.两个诱思问题1．WhatisthetheoryoftheSinaninventedbyZhangHeng?2．WhyweretheNauticalchartsnotabletobeusedbyCaptainBlighorZhengHe?【答案】1．Theinfluenceoftheterrestrialmagnetism.2．Becausetheinformationbegantobecollectedinthenineteenthcentury.SectionⅠReading(WarmingUp,Prereading，Reading&Comprehending)Ⅰ.根据词性及英文释义写出单词的正确形式1．n．kindness；forgiveness2．n．activityofexploring3．adj.aboveone'shead4．adj.atseanotfarfromland5．adj.madeordonewithoutanyplan6．adj.difficulttouse7．n．actofmentioning；actoflookingatforinformation8．adj.lightandthatcanbe(easily)carriedormoved【答案】1.mercy2.exploration3.overhead4.offshore5.random6.awkward7.reference8.portableⅡ.短语填空maywell；atthemercyof；workout；becloseto；thenumberof；comparewith；inrelationto；ratherthan1．Iprefertowalktheretakeabus.2．Theboatwastherapidriver.3．Thisnovelbecomeaclassic.4．thosewhoaresuffering，wearebetteroff.5．Ibelievethatyoucanthisproblembyyourself.【答案】1.ratherthan2.atthemercyof3.maywell4.Comparedwith5.workoutⅠ.阅读P12－13课文内容，从三个选项中选择最佳答案1．Howmanytraditionalmethodsusedbyseamenarementionedinthepassage?A．Four.B．Five.C．Eight.2．Thepassagedoesn'ttelluswhetherskilledseamenusedtousethetojudgehispositionatsea.A．NorthStarB．sunC．moon3．Bystudyingthewinds，seamencould．A．judgethedirectionoftheshipB．knowhowfarawaytheywerefromtheirhomeC．tellthedistancetheyhaddiscovered4．Fromthepassagewecanlearnthat．A．whyearlyseamenwantedtosailthesevenseasB．thereisusefulinformationinanencyclopediaC．earlysailorswentexploringtheseasusingtheirskillsandsimpleinstruments5．Thepurposeofthepassageistotellus．A．keepingalongitudeofthecoastlineisthefirstandmostusefulformofexplorationB．abouttheskills...
