Question: who represented uk in 1974 eurovision song contest
[{'answer': 'Olivia Newton - John', 'provenance': [{'wikipedia_id': '298498', 'title': 'United Kingdom in the Eurovision Song Contest 1974', 'start_paragraph_id': 1, 'start_character': 249, 'end_paragraph_id': 1, 'end_character': 276, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '298498', 'title': 'United Kingdom in the Eurovision Song Contest 1974', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 1338, 'bleu_score': 0.9804407632684461, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1267193945423872562}, 'section': 'Section::::Abstract.'}]}]