Question: who are the ghosts in a christmas carol
[{'answer': 'Christmas Past', 'provenance': [{'wikipedia_id': '73670', 'title': 'A Christmas Carol', 'start_paragraph_id': 1, 'start_character': 384, 'end_paragraph_id': 1, 'end_character': 398, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Present', 'provenance': [{'wikipedia_id': '73670', 'title': 'A Christmas Carol', 'start_paragraph_id': 1, 'start_character': 400, 'end_paragraph_id': 1, 'end_character': 407, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'answer': 'Yet to Come', 'provenance': [{'wikipedia_id': '73670', 'title': 'A Christmas Carol', 'start_paragraph_id': 1, 'start_character': 412, 'end_paragraph_id': 1, 'end_character': 423, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '73670', 'title': 'A Christmas Carol', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 494, 'bleu_score': 0.8261674229803011, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17481421824357332289}, 'section': 'Section::::Abstract.'}]}]