Do you know something about Braille(盲文)? Braille is the most well-known language system used by     22     people all over the world.

It is named after Louis Braille, who is the     23     of improving the way blind people read books by following raised(凸起的) letters.

Louis Braille was born on January 4, 1809, in France. He lost     24     eyesight by accident when he was 3. Louis Braille went to a special school for the blind in Paris in 1821. It was there that he     25     to read, using raised letters. However, because the raised     26     were made of paper pressed against copper wire(铜钱), the students never learned to write.

Later the school     27     a soldier to give a talk to the students. The talk     28     a system called night writing that allowed soldiers to communicate silently, even in the dark.

Braille was     29     in the system. He realized it could be used among blind people, too. He set out to work on it and in 1824， he introduced the reading and writing system. In 1829, Braille wrote his first book explaining his system.     30    , it was only after his death that the reading and writing system caught attention and     31     the most popular way for the blind to read and write around the world.