Question: where does the superior vena cava carry blood to
[{'answer': 'right atrium of the heart', 'provenance': [{'wikipedia_id': '242140', 'title': 'Superior vena cava', 'start_paragraph_id': 1, 'start_character': 161, 'end_paragraph_id': 1, 'end_character': 186, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '242140', 'title': 'Superior vena cava', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 676, 'bleu_score': 0.9318006973785801, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7349224047987945553}, 'section': 'Section::::Abstract.'}]}]