Question: what type of bus does pci express use
[{'answer': 'serial computer expansion bus standard', 'provenance': [{'wikipedia_id': '143320', 'title': 'PCI Express', 'start_paragraph_id': 1, 'start_character': 114, 'end_paragraph_id': 1, 'end_character': 152, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '143320', 'title': 'PCI Express', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 661, 'bleu_score': 0.784361909283064, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 7299522401299967629}, 'section': 'Section::::Abstract.'}]}]