21.Who invented Helicopter View Answer Report DiscussAnswer: BROQUETT Explanation:Currently no explanation available Improve this answer lets discuss in forum
22.Who invented Hydrogen View Answer Report DiscussAnswer: CAVENDISH Explanation:Currently no explanation available Improve this answer lets discuss in forum
23.Who invented Geometry View Answer Report DiscussAnswer: EUCLID Explanation:Currently no explanation available Improve this answer lets discuss in forum
24.Who invented Gun Powder View Answer Report DiscussAnswer: ROGER BACON Explanation:Currently no explanation available Improve this answer lets discuss in forum
25.Who invented Gramaphone View Answer Report DiscussAnswer: THOMAS ALVA EDISON Explanation:Currently no explanation available Improve this answer lets discuss in forum