In 1915, which Balkan nation joined W.W.I., on the side of the Central Powers (i.e. Germany), by declaring war on Serbia?
in 1915, which balkan nation joined w.w.i., on the side of the central powers (i.e. germany), by declaring war on serbia
FreebaseQA-train-8101.P0
germany
germany
m.0345h
military.military_combatant.military_conflicts..military.military_combatant_group.combatants
m.015qh
bulgaria