Warmingup、Pre-reading、Reading、Comprehending (6)

1、Unit 2 Sailing the oceans,Warming up、pre-reading、 reading look for special cloud formations or fog over streams to find land.,Use a compass.,Measure your position using the sun or stars; look for sea birds, cloud formations, fog or seaweed to show that land is nearby.,4. Read the passage again and u

2、se the information to analyze the navigational skills.,1. To find the ships position at sea a sailor used the North Star and the sun. 2. A sailor knew that land was nearby if he saw _ _. 3. Sailors used _ _to increase their speed.,fresh seaweed, nesting birds returning home in the evening or fog,sea

3、 currents or tides and winds,4. There were two methods to find longitude: 1)_ 2)_,measuring time and speed,compass and complicated mathematical tables,5 Write down the working principles of the following instruments: Bearing circle: Astrolabe:,to compare the height of the sun now with the position o

4、f the sun at midday.,to compare the position of the ship in relation to some stars or the sun,Quadrant:,a more precise form of the astrolabe, to measure how high stars are above the horizon, and compare that measurement with previous measurements (using the ship as one of the fixed points to find it

5、s position),Sextant:,an updated version of the quadrant and so it was more accurate, to measure the angle between two fixed points outside the ship (using two mirrors to find the ships position).,5. Imagine you are on a boat with twenty-nine other people. You have a small box for your personal thing

6、s but it can only hole ten items. What would you need for a weeks journey across the North Sea to England?,soap,blanket,cards, chess,shirt, trousers,knife, scissors,sea-sick tablets, cold medicine,novels, essay collections,waterproof boots,Read the passage (Reading) and decide whether the following

7、statements are true (T) or false (F). 1. An early method of calculating longitude was to use a knotted rope tied to a log. 2. The astrolabe was the first instrument to measure the suns position. 3. The quadrant was more precise and simplified than the astrolabe, but still had its shortcoming.,T,F,T,4. Up till now, the most accurate and reliable navigational instrument is the sextant. 5. The astrolabe, quadrant and sextant are different kinds of navigational instruments and they have nothing to do w