Question: who used morse code in world war 2
[{'answer': 'warships', 'provenance': [{'wikipedia_id': '18935', 'title': 'Morse code', 'start_paragraph_id': 17, 'start_character': 108, 'end_paragraph_id': 17, 'end_character': 116, 'bleu_score': 1.0, 'section': 'Section::::Development and history.\n'}]}, {'answer': 'naval bases', 'provenance': [{'wikipedia_id': '18935', 'title': 'Morse code', 'start_paragraph_id': 17, 'start_character': 125, 'end_paragraph_id': 17, 'end_character': 136, 'bleu_score': 1.0, 'section': 'Section::::Development and history.\n'}]}, {'answer': 'warplanes , especially by long - range patrol planes that were sent out by those navies to scout for enemy warships , cargo ships , and troop ships'}, {'provenance': [{'wikipedia_id': '18935', 'title': 'Morse code', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 0, 'bleu_score': 1.0, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15692620198311051922}, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '18935', 'title': 'Morse code', 'start_paragraph_id': 17, 'start_character': 0, 'end_paragraph_id': 17, 'end_character': 538, 'bleu_score': 0.9766041382465441, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 15692620198311051922}, 'section': 'Section::::Development and history.\n'}]}, {'provenance': [{'wikipedia_id': '18935', 'title': 'Morse code', 'section': 'Section::::Development and history.\n', 'start_paragraph_id': 17, 'end_paragraph_id': 17, 'meta': {'evidence_span': ['Radiotelegraphy using Morse code was vital during World War II, especially in carrying messages between the warships and the naval bases of the belligerents', 'Radiotelegraphy using Morse code was vital during World War II, especially in carrying messages between the warships and the naval bases of the belligerents.', 'Radiotelegraphy using Morse code was vital during World War II, especially in carrying messages between the warships and the naval bases of the belligerents. Long-range ship-to-ship communication was by radio telegraphy, using encrypted messages because the voice radio systems on ships then were quite limited in both their range and their security. Radiotelegraphy was also extensively used by warplanes, especially by long-range patrol planes that were sent out by those navies to scout for enemy warships, cargo ships, and troop ships.']}}]}]