Question: when were the first jets used in war
[{'answer': '1944', 'provenance': [{'wikipedia_id': '17366750', 'title': 'First-generation jet fighter', 'start_paragraph_id': 8, 'start_character': 198, 'end_paragraph_id': 8, 'end_character': 202, 'bleu_score': 1.0, 'section': 'Section::::World War II era.:Aircraft that entered service.\n'}]}, {'provenance': [{'wikipedia_id': '17366750', 'title': 'First-generation jet fighter', 'start_paragraph_id': 8, 'start_character': 0, 'end_paragraph_id': 8, 'end_character': 1713, 'bleu_score': 0.9811093037167501, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17957265021812754840}, 'section': 'Section::::World War II era.:Aircraft that entered service.\n'}]}]