Question: which type of bond represents a single weak chemical bond
[{'answer': 'sigma bond', 'provenance': [{'wikipedia_id': '1390921', 'title': 'Single bond', 'start_paragraph_id': 3, 'start_character': 28, 'end_paragraph_id': 3, 'end_character': 38, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '1390921', 'title': 'Single bond', 'start_paragraph_id': 3, 'start_character': 0, 'end_paragraph_id': 3, 'end_character': 570, 'bleu_score': 0.9815648442794911, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 17288283462705215205}, 'section': 'Section::::Abstract.'}]}]