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Publication of BE693201ApublicationCriticalpatent/BE693201A/xx
G09B—EDUCATIONAL OR DEMONSTRATION APPLIANCES; APPLIANCES FOR TEACHING, OR COMMUNICATING WITH, THE BLIND, DEAF OR MUTE; MODELS; PLANETARIA; GLOBES; MAPS; DIAGRAMS
G09B3/00—Manually or mechanically operated teaching appliances working with questions and answers
G09B3/02—Manually or mechanically operated teaching appliances working with questions and answers of the type wherein the student is expected to construct an answer to the question which is presented or wherein the machine gives an answer to the question presented by a student
G09B3/04—Manually or mechanically operated teaching appliances working with questions and answers of the type wherein the student is expected to construct an answer to the question which is presented or wherein the machine gives an answer to the question presented by a student of chart form