Question: when did china become a member of the un
[{'answer': '1945', 'provenance': [{'wikipedia_id': '325572', 'title': 'China and the United Nations', 'start_paragraph_id': 2, 'start_character': 165, 'end_paragraph_id': 2, 'end_character': 169, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '325572', 'title': 'China and the United Nations', 'start_paragraph_id': 2, 'start_character': 0, 'end_paragraph_id': 2, 'end_character': 1085, 'bleu_score': 0.847263439544351, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1136250272075895589}, 'section': 'Section::::Abstract.'}]}]