Question: when was the first roman invasion of britain
[{'answer': 'AD 43', 'provenance': [{'wikipedia_id': '39847', 'title': 'Roman conquest of Britain', 'start_paragraph_id': 1, 'start_character': 78, 'end_paragraph_id': 1, 'end_character': 83, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '39847', 'title': 'Roman conquest of Britain', 'start_paragraph_id': 5, 'start_character': 0, 'end_paragraph_id': 5, 'end_character': 452, 'bleu_score': 0.6810096582703631, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5398299837123409401}, 'section': 'Section::::Background.\n'}]}]