1、GPS(global positioning system)Zheng He1371-1433He led a large fleet to explore Southeast Asia,India and the Middle East in the Ming Dynasty.Altogether he made 7 voyages in the 15th century.Marco Polo1254-1324He is the most famous westerner to travel the Silk Road.While in prison,he told the story of
2、 his travels to a fellow prisoner who wrote his adventures down.When the book the travels of Marco Polo was published,it became a best-seller.Scan the whole text and make a mind-map.Mind-mapMain ideaHowseamen exploredthe oceans before 17Cnaturecoastlinecelestial bodies North StarSunwildlifeseaweedbi
3、rdsweatherseacloudsfogwindsnavigational instrumentslongitudelatitudethe Bearing Circlethe Astrolabe the Quadrantthe Sextant knotted ropecompass&mathsComprehend your geographical knowledge and discuss the methods you are familiar with and share with others.(Make a diagram if necessary)Students workWork in pairs to deal with the situations.Assume that you are lost in the sea in the day,how can you tell directions?Assume that you are lost in the sea at night,how can you tell directions?
