Question: where is essex and herts air ambulance based
[{'answer': 'Earls Colne Airfield', 'provenance': [{'wikipedia_id': '30784455', 'title': 'Essex & Herts Air Ambulance', 'start_paragraph_id': 3, 'start_character': 204, 'end_paragraph_id': 3, 'end_character': 224, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '30784455', 'title': 'Essex & Herts Air Ambulance', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 249, 'bleu_score': 0.779219286167383, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 5088145898964702678}, 'section': 'Section::::Abstract.'}]}]