Warming up、Pre-reading、Reading、ComprehendingPPT专用课堂实录内容

Unit 2 book 9 Sailing the Oceans 教学设计

Teaching Aim Let the students to know the difference between a navigator and an explorer. To learn how seamen explored the oceans before the 17th century and learn their qualities Teaching process Warming up What is the difference between a navigator and an explorer?

Pre-reading

The four basic instruments for navigation:

Reading

Decide whether the following 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 sun’s position.

3. The quadrant was more precise and simplified than the astrolabe, but still had its shortcoming.

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 with

each other.

Read the passage and answer the following questions.

1.What’s the main idea of the passage?

The reading passage explains how seamen explored the oceans and what kind of navigational instruments were used to sailors before the seventeeth century

2.What is the use of a bearing circle,

astrolabe, quadrant or sextant? (

)

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

3.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 or change in your position in relation to

the stars.

4. Why is the position of the sun and various stars useful for working out latitude?

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 ship's position.

Discussion

Suppose you were a sea captain aiming to

sail round Africa. Discuss in groups:

What skills would you seek in your sailors?

Summary

Read the passage again and use the information to analyze the navigational skills.

1. To find the ship’s 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.

4. There were two methods to find longitude:

1)_______________________

2)__________________________________

Homework

1. Review this passage. 2. Preview Learning about language.