Question: which class of the enzymes can be used to join two fragments of dna
[{'answer': 'DNA ligase', 'provenance': [{'wikipedia_id': '8697', 'title': 'DNA ligase', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 10, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '8697', 'title': 'DNA ligase', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 575, 'bleu_score': 0.9344621062860431, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 1057275644475623187}, 'section': 'Section::::Abstract.'}]}]