Question: what do you use coins for in trivia crack
[{'answer': 'power - up', 'provenance': [{'wikipedia_id': '44774310', 'title': 'Trivia Crack', 'start_paragraph_id': 21, 'start_character': 23, 'end_paragraph_id': 21, 'end_character': 35, 'bleu_score': 1.0, 'section': 'Section::::Power-ups and coins.\n'}]}, {'provenance': [{'wikipedia_id': '44774310', 'title': 'Trivia Crack', 'start_paragraph_id': 17, 'start_character': 0, 'end_paragraph_id': 17, 'end_character': 419, 'bleu_score': 0.972782728923768, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 3442275511623036621}, 'section': 'Section::::Power-ups and coins.\n'}]}]