NCE3_lesson17(共19页).ppt

* * lesson 17 The longest suspension bridge in the world Topics for discussion 1 Tell us what you know about any great construction in this country. 2 Tell us about famous bridges of the world you know about. 3 How has modern technology affected the work of architects and engineers? the introduction of the story Today well talk about the longest bridge of the 196os in the world. Whats the longest suspension bridge today? The longest suspension bridge in the world is currently the Akashi-Kaikyō Bridge, also known as the Pearl Bridge. It links the Japanese city of Kobe on the mainland of Honshū to Iwaya on Awaji Island. The total length of all three spans of the bridge is 3,911 metres, while the central span has a length of 1,991 metres. The bridge was opened for traffic on 5 April 1998. The Indonesian government has approved the Sunda Strait Bridge which, if completed, will be the worlds longest suspension bridge, with a total length of 26 km. reading and listening Read the story and see if you can answer the following question: How is the bridge supported? Two great towers support four huge cables from which the bridge is suspended. comprehension questions 1. When did Verrazano sail into NewYork Harbour? 2.What did he call it? 3. How did Verrazano describe New York Harbour? 4. Why will Verrazanos name be remembered? 5. Who was the bridge designed by? 6.What does the bridge join? 7. Whats its span? 8. What did Amman have to take account of when designing the bridge? 9.What do the two great towers do ? 10. What are the towers built on? 11. How far down do these platforms extend? 12. How tall are the two towers? 13. What is the bridge suspended from? 14. Why are these cables so strong? 15. Why doesnt the bridge collapse when it is packed with cars? The Verrazano Bridge, which joins Brooklyn to Staten Island,has a span of 4,260 feet. Its two great towers support four huge cables. The towers are built on platforms made of steel and concrete,extend