2015-07-21
680
I. What can it be?
Cnosurtcniot, ceniveratl, beidgr, grried, tsrsu, peri, snespsionu
II. Decide whether the following statements are true or false according to the text:
1. Logs or vines across streams served as the first bridges.
2. A bridge on the suspension principle was made by people in the Middle Ages by means of handrails.
3. The Incas of Peru used beam bridges made of six strong cables.
3. An arch bridge is known to be the first bridge.
4. Another name for a drawbridge is a cantilever bridge.
5. Designers of the 19th century had to meet the demand for greater heights, spans, and strength.
6. Railroads expansion made iron trusses be replaced by stone arches.
7. Since late 1800s reinforced concrete has been chiefly used in bridge construction.
8. A steel-and-concrete girder bridge was one of the most commonly used bridge designs in the 20th century.
III. Answer the following questions:
1. What are the earliest types of bridges?
2. What periods in bridge construction can you distinguish?
3. What is the principle of a suspension bridge?
4. How can you explain the fact that drawbridges were mainly built in the Middle Ages?
5. What was the reason of adding additional support to a basic beam bridge in the 19th century?
6. What was Sir Henry Bessemer famous for? In what way did his invention develop bridge construction?
7. When did large-scale bridge building start? What are the reasons?
8. What does current research focus on?
