Question: when did britain leave the league of nations
[{'answer': 'permanent members', 'provenance': [{'wikipedia_id': '17926', 'title': 'League of Nations', 'start_paragraph_id': 3, 'start_character': 256, 'end_paragraph_id': 3, 'end_character': 273, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '17926', 'title': 'League of Nations', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 757, 'bleu_score': 0.9104407015262461, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 11265549165597201905}, 'section': 'Section::::Abstract.'}]}]