Giúp mình vs ạ!
Read the text on the tight about the invention of semaphore. Five sentences have been removed. Choose from sentences A-F the one which fits each gap (l-4).There is one extra sentence which you do not need. There is an example at the beginning (0).
A Using ropes, these could be moved to form 49 different shapes that could be recognized easily.
B The main problem was that it could not be used during the night or on foggy days.
C These messages could be sent very quickly.
D The new republic faced enemies on all sides in the form of the forces of Britain, Austria, Holland, Prussia and Spain.
E In August 1794, it carried its first message, the news of Napoleon's victory at Le Quenoy.
F A system was built between London and the south coast, and other countries followed.
War has been called 'the mother of invention', and this was certainly true in the French Revolutionary wars in 1792. 1 | D | What the Revolutionary Government urgently needed was a reliable system of communication.
Claude Chappe, who was a priest and an engineer, had developed a telegraph system, but had not been able to test it fully. However, his brother Ignace was a member of the government, and arranged for Claude's system to be tested. It turned out to be a great success and started a new form of high-speed communication.
The two brothers had a series of towers built 5 to 10 km apart. At the top of each tower was a tall wooden mast, and they attached one horizontal and two vertical wooden beams to this mast. Claude called this system 'semaphore', which comes from the Greek meaning 'bearing a sign'. 2 ( )
Operators in each tower watched neighbouring towers through a telescope and then passed the message on to the next one in the line. The first line stretched from Paris to Lille, a distance of 2.40 km. 3 ( ). At an average speed of three signals a minute, it was carried in 20 minutes, more than 90 times faster than messengers on horseback.
Once the value of Chappe's system was understood, it soon became the standard method of communication in Europe. 4 ( ). By the time the electric telegraph was developed, France had more than 550 semaphore towers stretching 4,800km.
Unfortunately, Chappe's system had some disadvantages. 5 ( ) The towers were also expensive to maintain and the cost of staff was high. In the end, Chappe was depressed by these criticisms of his inventions and by claims from other engineers that they had invented semaphore, and he committed suicide in 1805.
