-who were Buster Keaton, Charlie Chaplin and Harold Lloyd and why were they so influential?

Buster Keaton: American film comedian and director. Known for his deadpan expression and his imaginative and visual comedy eg. The General (1927)

Charlie Chaplin: One of the greatest silent movie stars and director made popular and funniest films of his time eg. The Great Dictator (1940)

Harold Lloyd: American film actor and producer. he made 200 comedy films. eg. safety last. (1923)