Question: when did china become a member of the wto
[{'answer': '11 December 2001', 'provenance': [{'wikipedia_id': '36014953', 'title': 'China and the World Trade Organization', 'start_paragraph_id': 1, 'start_character': 63, 'end_paragraph_id': 1, 'end_character': 79, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '36014953', 'title': 'China and the World Trade Organization', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 284, 'bleu_score': 0.957870874785216, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9899993365980667163}, 'section': 'Section::::Abstract.'}]}]