Question: what country did not join the league of nations
[{'answer': 'the United States', 'provenance': [{'wikipedia_id': '614945', 'title': 'Member states of the League of Nations', 'start_paragraph_id': 5, 'start_character': 58, 'end_paragraph_id': 5, 'end_character': 75, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '614945', 'title': 'Member states of the League of Nations', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 110, 'bleu_score': 0.8852140475440831, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3601941378756429815}, 'section': 'Section::::Abstract.'}]}]