(a) — blind people cannot (b) —, their sense of (c) — becomes far more (d) — than that of most sighted people. This ability was put to use by a brilliant man (e) — Louis Braille. In the early 19th century, he invented a (f) — of writing which (g) — his name. The Braille system reproduces the letters of the alphabet by a series (h) — in certain positions which are raised on the paper. The blind person runs the (i) — of his fingers across the pages of the Braille book and can work out the letters and numbers (j) — there.