新人教选修9 Unit2 Sailing the oceans-Reading

Unit2SailingtheOceansPeriod1.ReadingTeachingaims:1.Letthestudentstoknowthedifferencebetweenanavigatorandanexplorer.2.Tolearnhowseamenexploredtheoceansbeforethe17thcenturyandlearntheirqualitiestheArcticOceantheIndianOceanthePacificOceantheAtlanticOceanWarmingupWhatisthedifferencebetweenanavigatorandanexplorer?NavigatorseanauticalinstrumentsfindnewislandsorcontinentsNavigatorissomebodywhofindsthepositionandplotsthecourseofashipusingmapsandinstruments.ExplorerlanduseofcompassandlandmarksfindnewplaceswithinanalreadyidentifiedislandorcontinentExplorerissomebodywhotravelsintoorthroughaplaceinordertolearnaboutit.Veryoftennavigatorsarealsoexplorers.Intheyearbetween1405and1433,sevenlargetreasurefleetssailedwestwardsonvoyagesoftradeandexploration.UnderthecommandofZhengHe,thefleetssetsailfromtheSouthChinaSeaacrosstheIndianOceantotheRedSea,andthentraveledfurthersouth,discoveringtheeasterncoastofAfrica.About700yearsagoayoungtraderfromItalytookalongtriptoCathay.CathayisknownasChinatoday.Hewentwithhisfatheranduncle,whohadtraveledthereoncebefore.TheystayedinChinaforabouttwodecades.Theyoungman'snamewasMarcoPolo.HewaslikedbytheleaderinChinaatthetime.JamesCookJamesCook(1728-1779)wasthegreatestBritainnavigator.CookenlistedintheRoyalNavyin1755.In1768hewaspromotedandsenttothePacificwherehesurveyedTahiti,NewZealand,andAustralia.Onhisfamoussecondexpedition(1772-1775)heexploredAntarctica.In1776heundertookhisthirdandfinalvoyageinwhichheexploredtheWestCoastofNorthAmericaandtriedtolocateapassagebetweentheAtlanticandPacificoceans.OnthisvoyagehediscoveredtheHawaiianIslands,andsailedupthecoastofNorthAmericathroughtheBeringStraitstotheArcticOcean.OnhisreturnhewaskilledbyHawaiianislanders.Pre-readingThefourbasicinstrumentsfornavigation:Sinan,theancientChinesecompass.ItwasinventedbyZhangHengintheHandynasty.astrolabesextantquadrantnauticalchartDecidewhetherthefollowingstatementsaretrue(T)orfalse(F).1.Anearlymethodofcalculatinglongitudewastouseaknottedropetiedtoalog.2.Theastrolabewasthefirstinstrumenttomeasurethesun’sposition.3.Thequadrantwasmorepreciseandsimplifiedthantheastrolabe,butstillhaditsshortcoming.TFT4.Uptillnow,themostaccurateandreliablenavigationalinstrumentisthesextant.5.Theastrolabe,quadrantandsextantaredifferentkindsofnavigationalinstrumentsandtheyhavenothingtodowitheachother.FFReadthepassageandanswerthefollowingquestions.1.What’sthemainideaofthepassage?ThereadingpassageexplainshowseamenexploredtheoceansandwhatkindofnavigationalinstrumentswereusedtosailorsbeforetheseventeethcenturyComprehending2.Whatistheuseofabearingcircle,astrolabe,quadrantorsextant?()Whatistheuseofacompass?()A.TosetthecourseoftheshipB.TomeasurethepositionoftheshipC.TomeasurethespeedoftheshipD.TotellthetimeAB3.Whyarespeedandtimeimportantinworkingoutthelongitudeofaship?Becausetheearthmovesfifteendegreeswestwardseveryhour.Ifyouknowyourdirection,speedandtime,youcanworkouttheapproximatelongitudeorchangeinyourpositioninrelationtothestars.4.Whyisthepositionofthesunandvariousstarsusefulforworkingoutlatitude?Becausetheyarefixedpointsintheskyandtheirmovementsinrelationtotheeartharealreadyknown.Sotheycanbeusedtomeasureaship'sposition.DiscussionSupposeyouwereaseacaptainaimingtosailroundAfrica.Discussingroups:Whatskillswouldyouseekinyoursailors?Thesailorswouldneedtobeexcellentnavigators,abletocopewithbothhotandcoldweather,experiencedinsailingthroughverybadweatherandabletocooperateinateamSummaryReadthepassageagainandusetheinformationtoanalyzethenavigationalskills.Usingnature1.Tofindtheship’spositionatseaasailorusedtheNorthStarandthesun.2.Asailorknewthatlandwasnearbyifhesaw________________________________________________________.3.Sailorsused________________________________toincreasetheirspeed.freshseaweed,nestingbirdsreturninghomeintheeveningorfogseacurrentsortidesandwinds4.Thereweretwomethodstofindlongitude:1)_______________________2)__________________________________Usinginstrumentsmeasuringtimeandspeedcompassandcomplicatedmathematicaltables5Writedowntheworkingprinciplesofthefollowinginstruments:Bearingcircle:Astrolabe:tocomparetheheightofthesunnowwiththepositionofthesunatmidday.tocomparethepositionoftheshipinrelationtosomestarsorthesunQuadrant:amorepreciseformoftheastrolabe,tomeasurehowhighstarsareabovethehorizon,andcomparethatmeasurementwithpreviousmeasurements(usingtheshipasoneofthefixedpointstofinditsposition)Sextant:anupdatedversionofthequadrantandsoitwasmoreaccurate,tomeasuretheanglebetweentwofixedpointsoutsidetheship(usingtwomirrorstofindtheship'sposition).Consolidation.Wemaywanttoknow(1)____seamenexploredtheoceans(2)_______latitudeappeared.(3)_______theydidn’thavethemodernnavigationalhelp,seamencouldstillcontroltheseabyusingsomeskillstoexploreseasanddiscoverthenewlands.(4)______(use)natureisthefirstandmostusefulformof(5)_________(explore),suchasusingcelestialbodies,usingwildlife,usingtheweather,andusingthesea.Becauseoftheseskill,sailorsincreasedtheability(6)__navigatenewseaswhentheyusedinstruments,(7)______(include)longitudeandlatitude.howbeforeThoughUsingexpl