IV. Discourse      Braille, a system for raised dots on paper, has been revolutionary for people with blindness. It is a codethat enables millions of blind people to read and write in many different languages. The story of braille beginswith Charles Barbier, who believed that conventional writing was at times a barrier to literacy. __52__ Thesystem was composed of cells with two columns, each with six dots arranged vertically. The dots could be raisedto indicate a phonetic sound on a corresponding six-by-five grid. __53__      In 1821, Barbier wrote to the Royal Institute for Blind Youth, an establishment in Paris, to tell the directorabout his invention. __54__ Reading raised type was difficult, and students could not produce their own writingusing Haüy’s method. Barbier’s system represented an enormous leap forward in the students’ education.      Among the students at the institute was a young boy named Louis Braille, who was astonished when hefirst touched the raised dots of Barbier’s writing system. __55__ Braille improved on Barbier’s system in thefollowing years, modifying it until he arrived at a simplified, six-dot system. __56__ With 64 possiblecombinations, the cells could also represent various symbols. In 1824, when he was only 15 years old, Brailleunveiled this system. Then, in 1829, he published his first book on what is known today as braille.  
【題組】52.(AB) In 1815, he proposed an alternative writing system based on the Polybius square.(AC) Braille immediately identified its merits, but he was also quick to notice the system’s flaws.(AD) Braille can be written using a braille writer, an electronic braille notetaker or with the use of a computerconnected to a braille embosser.(AE) At that time, students at the institute read by feeling raised type, a method developed by the school’sfounder, Valentin Haüy.(BC) The number and arrangement of raised dots in Braille’s cells could represent any letter of the alphabet ina space no larger than a fingertip.(BD) For example, a cell with four raised dots in the first column and three in the second represented the soundin the fourth row and third column of the grid.