【題組】56.(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.