Question: hcl is an example of an acid or base
[{'answer': 'acid', 'provenance': [{'wikipedia_id': '3038', 'title': 'Acid–base reaction', 'start_paragraph_id': 1, 'start_character': 3, 'end_paragraph_id': 1, 'end_character': 7, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '3038', 'title': 'Acid–base reaction', 'start_paragraph_id': 32, 'start_character': 0, 'end_paragraph_id': 32, 'end_character': 126, 'bleu_score': 0.9021315316859231, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 8833051774455182804}, 'section': 'Section::::Acid–base definitions.:Brønsted–Lowry definition.\n'}]}]