Question: where is the sternum located on the human body
[{'answer': 'the center of the chest'}, {'provenance': [{'wikipedia_id': '30270392', 'title': 'Sternum', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 474, 'bleu_score': 0.946458428441119, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16943304392946863086}, 'section': 'Section::::Abstract.'}]}]