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1、新课标人教版课件系列《高中英语》选修(模块）9-2.1Inpairsdiscussthesequestions:1Whatisanavigator?Anavigatorexploresnewroutesacrossthesea.2Whatisthedifferencebetweenanavigatorandanexplorer?Anavigatorexploresthesea;anexplorerdiscoversnewplacesonland.WarmingUp3Lookatthesefamouspeople.Aretheynavigatorsorexplorers?What
2、doyouknowaboutthem?NavigatorseanauticalinstrumentsfindnewislandsorcontinentsNavigatorissomeonewhofindsthepositionandplotsthecourseofaship,anaircraft,acar,etc,usingmapsandinstruments.ExplorerlanduseofcompassandlandmarksfindnewplaceswithinanalreadyidentifiedislandorcontinentExplorerissomeonewh
3、otravelsintoorthroughaplaceinordertolearnaboutit.Veryoftennavigatorsarealsoexplorers.Lookatthepictures.Thenanswerthequestions.1Howdoyouthinkseamenfoundtheirwaybeforemodernaccuratemethodsofnavigationwereinvented?Keptclosetotheshore,usednaturesuchasthesun,wind,birds,tide,etc,tohelpthem,andused
4、someoftheinstrumentsincludingacompass,astrolabe,etc.Pre-reading2Whichdoyouthinkwaseasiertoworkout:latitudeorlongitude?Latitude,becauseitwasusedtomeasurehowfaryouhadtravelledfromlandonastraightline.Itwasdiscoveredalongtimebeforelongitude.3Canyouidentifytheseearlynavigationalinstrumentsseamenu
5、sedandexplainhowtheyareused?1_________________________2_________3_________4________________________4Whichonesdoyouthinkarestillusedtoday?Seachartsarestillusedtoday.compass(inancientChina)astrolabesextantsea/nautical/marinechartReadthepassageandanswerthefollowingquestions.1Whatistheuseofabear
6、ingcircle,astrolabe,quadrantorsextant?()Whatistheuseofacompass?()AtosetthecourseoftheshipBtomeasurethepositionoftheshipCtomeasurethespeedoftheshipDtotellthetimeComprehending1BA2Whyarespeedandtimeimportantinworkingoutthelongitudeofaship?Speedandtimeareimportantinfindingoutthelongitudeofashipb
7、ecausetheearthmovesfifteendegreeswestwardseveryhour.Ifyouknowyourdirection,speedandtime,youcanworkouttheapproximatelongitudeorchangeinyourpositioninrelationtothestars.3Whyisthepositionofthesunandvariousstarsusefulforworkingoutlatitude?Thepositionof
