A、1520. B、6020. C、1755. D、1620. DWhen was the first book of sign language published?

It was in the sixteenth century that Geronimo Cardano, a physician of Padua, in northern Italy, proclaimed that deaf people could be taught to understand written combinations of symbols by associating them with the thing they represented. The first book on teaching sign language to deaf people that contained the manual alphabet was published in 1620 by Juan Pablo de Bonet.
    In 1755 Abbe Charles Michel de L’Epee of Paris founded the first free school for deaf people. He demonstrated that deaf people could develop communication with themselves and the hearing world through a system of conventional gestures, hand signs, and fingerspelling. He created and demonstrated a language of signs whereby each would be a symbol that suggested the concept desired.
    The abbe was apparently a very creative person, and the way he developed his sign language system was by first recognizing, then learning the signs that were already being used by a group of deaf people in Paris. To this knowledge he added his own creativeness that resulted in a signed version of spoken French. He paved the way for deaf people to have a more standardized language of their own—one which would effectively bridge the gap between the hearing and non-hearing worlds.