Question: what is the leading source of energy used in china
[{'answer': 'Coal', 'provenance': [{'wikipedia_id': '11588698', 'title': 'Energy policy of China', 'start_paragraph_id': 30, 'start_character': 11, 'end_paragraph_id': 30, 'end_character': 15, 'bleu_score': 1.0, 'section': 'Section::::Fossil fuels.\n'}]}]