Question: what type of reaction is acid and base
[{'answer': 'metathesis', 'provenance': [{'wikipedia_id': '6271', 'title': 'Chemical reaction', 'start_paragraph_id': 22, 'start_character': 319, 'end_paragraph_id': 22, 'end_character': 329, 'bleu_score': 1.0, 'section': 'Section::::Elementary reactions.\n'}]}, {'provenance': [{'wikipedia_id': '6271', 'title': 'Chemical reaction', 'start_paragraph_id': 22, 'start_character': 0, 'end_paragraph_id': 22, 'end_character': 329, 'bleu_score': 0.963949056609222, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 9533351627273139928}, 'section': 'Section::::Elementary reactions.\n'}]}]