Unit 2 Sailing the oceans课件 新人教版选修.ppt

《Unit 2 Sailing the oceans课件 新人教版选修.ppt》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、SailingtheoceansUnit2Wordsminimumpoleoverheadoffshoreoutwardsecuremagneticadj.最小的;最低的n.地极;柱;杆adj.在头上的adv.在头顶上;在空中adj.离岸的;海面上的adj.外面的;向外的adv.向外;在外adj.安全的;可靠的adj.磁的;有磁性的awkwardreferenceprecisesimplifyportableshortcomingupdatedtendencyreliableadj.难使用的;笨拙的n.参考adj.精确的;准确的vt.单一化;简单化adj.轻便的;手提的n.缺

2、点;短处vt.更新n.趋向;倾向adj.可靠的;可信赖的1Whatisanavigator?2Whatisthedifferencebetweenanavigatorandanexplorer?WarmingUpInpairsdiscussthesequestions:Anavigatorexploresnewroutesacrossthesea.Anavigatorexploresthesea;anexplorerdiscoversnewplacesonland.3Lookatthesefamouspeople.Aretheynavigatorsorexplorers?Wh

3、atdoyouknowaboutthem?ZhengHe,intheyearbetween1405and1433,sevenlargetreasurefleetssailedwestwardsonvoyagesoftradeandexploration.UnderthecommandofZhengHe,thefleetssetsailfromtheSouthChinaSeaacrosstheIndianOceantotheRedSea,andthentraveledfurthersouth,discoveringtheeasterncoastofAfrica.Herenewe

4、drelationswiththeKingdomsoftheEastAfrican.WhenMarcoPolowasstillveryyoung,hedecidedtotraveltogetherwithhisfather.IttookthemmorethanthreeyearstotraveltoChina.Afternearlyseventeenyears’travelintheEast,Marcoandhisfatherwantedtoreturnhome.MarcoPoloMarcoPolowasborninVenicein1254.Hewasthemostfamou

5、sforeignertovisitAsiaduringtheMiddleAges.JamesCook(1728-1779)wasthegreatestBritainnavigator.CookenlistedintheRoyalNavyin1755.In1768hewaspromotedandsenttothePacificwherehesurveyedTahiti,NewZealand,andAustralia.Onhisfamous2ndexpedition(1772-75)heexploredAntarctica.In1776inhisthirdandfinalvoya

6、ge,heexploredtheWestcoastofNorthAmericaanddiscoveredtheHawaiianIslands.Navigatorissomeonewhofindsthepositionandplotsthecourseofaship,anaircraft,acar,etc,usingmapsandinstruments.NavigatorseanauticalinstrumentsfindnewislandsorcontinentsExplorerissomeonewhotravelsintoorthroughaplaceinordertole

7、arnaboutit.Veryoftennavigatorsarealsoexplorers.Explorerlanduseofcompassandlandmarksfindnewplaceswithinanalreadyidentifiedislandorcontinent1Howdoyouthinkseamenfoundtheirwaybeforemodernaccuratemethodsofnavigationwereinvented?Pre-readingLookatthepicturesonp