Question: what is the speed of light in km
[{'answer': '300,000 km / s'}, {'provenance': [{'wikipedia_id': '28736', 'title': 'Speed of light', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 1009, 'bleu_score': 0.538160827516535, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7460556038066944260}, 'section': 'Section::::Abstract.'}]}]