What was first demonstrated by Alexander Graham Bell at the Philadelphia Exhibition in 1876?
what was first demonstrated by alexander graham bell at the philadelphia exhibition in 1876
FreebaseQA-train-713.P0 FreebaseQA-train-713.P1
alexander graham bell alexander graham bell
alexander graham bell alexander graham bell
m.0k70 m.0k70
base.argumentmaps.innovator.original_ideas user.lindenb.default_domain.scientist.known_for
m.07cx4
telephone
m.07cx4
telephone