Warmingup、Pre-reading、Reading、Comprehending (5).pptx

1、Sailing the oceans,warming up,( 5 minutes ),Sailing,Question: How many oceans are there in the world ?,Pacific Ocean,Atlantic Ocean,Indian Ocean,Arctic Ocean,world map exploration,Write down the words you know, which are related to navigation and sea .,navigation,sail, sailor, voyage, latitude, long

2、itude, equator, horizon, captain, land island, nautical middles, explore, exploration,sea,seaman, seaweed, seafood, shore, offshore, onshore, beach, beach-ball, seabed, sea-bird, seagull, sea shell, seaside, sea water, seasick, coast, coastline, tide, wave, current,Pre-reading,( 5 minutes ),compass,

3、Astrolabe(星盤(pán)),Sextant(六分儀),sea/nautical chart,navigators,early navigational instruments,What is a navigator? What is the difference between a navigator and an explorer?,A navigator explores new routes across the sea.,A navigator explores the sea; an explorer discovers new places on land.,Zheng He,Is

4、 he a navigator or an explorer ?,He made seven voyages during his lifetime and contributed greatly to the science of navigation in China.,Zheng He,Marco Polo,James Cook,How do you think seaman found their way before modern accurate methods of navigation were invented ? How did they navigate so well

5、?,reading,Read about what navigation was like before modern instruments were used.,( 25 minutes ),Sailing the oceans,Fast-reading to get the general idea.,Page 1,( 10 minutes ),Using nature,Keeping alongside the coastline Using celestial bodies Using wildlife Using the weather Using the sea,( 1 minu

6、te ),Using celestial bodies,to plot the positions,to work out the latitude,a special cloud formation indicates there is land close by,( 2 minutes ),Using wildlife,If seaweed was fresh and smelled strongly, the ship was close to land.,Sea birds could be used to show the way to land when it was nowher

7、e to be seen.,( 1 minute ),Using the weather,fog,To help identify the position of a stream or river when,To direct their sailing,( 1 minute ),. Use the information to analyze the navigational skills and write the answers in your own words.,To find the ships position at sea a sailor used _. A sailor

8、knew that land was nearby if he saw_ _. Sailors used _ _ to increase their speed.,the North Star and the sun.,sea currents or tides and,winds,Using nature,clouds , fresh seaweed,nesting birds or fog,( 5 minutes ),Fast-reading to get the general idea. then answer the questions.,Page 2,( 10 minutes ),

9、Using navigational instruments,1. Finding longitude,2. Finding latitude,the compass,the bearing circle (方位圓),the astrolabe (星盤(pán)),the quadrant (象限儀,四分儀),the sextant (六分儀),( 2 minutes ),Read the passage and answer the following questions.,What is the use of a bearing circle, astrolabe, quadrant or sext

10、ant? ( ) What is the use of a compass? ( ) A. to set the course of the ship B. to measure the position of the ship C. to measure the speed of the ship D. to tell the time,B,A,Using instruments,( 2 minutes ),Read again and fill in the blanks,There were two methods to find longitude: 1. _ 2._,measurin

11、g time and speed,compass and complicated,mathematical tables,Using instruments,( 1 minute ),Write down the working principles of the following instruments:,Bearing circle: Astrolabe: Quadrant: Sextant:,to compare the height of the sun now with the position of the sun at midday.,to compare the positi

12、on of the ship in relation to some stars or the sun.,a more precise form of the astrolabe, to measure how high stars are above the horizon, and compare that measurement with previous measurements.,an updated version of the quadrant and so it was more accurate, to measure the angle between tow fixed

13、pints outside the ship.,( 5 minutes ),horizon,Sun height,A Bearing Circle,Bearing the sun- height and azimuth,(The marks were used to measure the shadow of the sun and its height and position in the sky.),(方位),Listen to the tape and then answer the questions,Detailed reading,Page 2,( 5 minutes ),1.

14、Why are speed and time important in working out the longitude of a ship?,Because the earth moves fifteen degrees westwards every hour. If you know your direction, speed and time, you can work out the approximate longitude.,2. Why is the position of the sun and various stars useful for working out la

15、titude?,Because they are fixed points in the sky and their movements in relation to the earth are already known. So they can be used to measure a ships position.,( 10 minutes ),discussion,What would you do if you came across the following problems during your voyage?,wait till the storm is over, and

16、 then find your new position and return to your original course,use knots to find your speed and work out your approximate longitude,use the compass and the astrolabe, quadrant or sextant to find out your position, return to your former course.,follow nesting birds to shore; look for special cloud formations or fog