Question: what are the two types of mixtures in science
[{'answer': 'homogeneous', 'provenance': [{'wikipedia_id': '286069', 'title': 'Mixture', 'start_paragraph_id': 4, 'start_character': 23, 'end_paragraph_id': 4, 'end_character': 34, 'bleu_score': 1.0, 'section': 'Section::::Characteristics of mixtures.\n'}]}, {'answer': 'heterogeneous', 'provenance': [{'wikipedia_id': '286069', 'title': 'Mixture', 'start_paragraph_id': 4, 'start_character': 38, 'end_paragraph_id': 4, 'end_character': 51, 'bleu_score': 1.0, 'section': 'Section::::Characteristics of mixtures.\n'}]}, {'provenance': [{'wikipedia_id': '286069', 'title': 'Mixture', 'start_paragraph_id': 4, 'start_character': 0, 'end_paragraph_id': 4, 'end_character': 379, 'bleu_score': 0.968982777549629, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 6471587761629672687}, 'section': 'Section::::Characteristics of mixtures.\n'}]}]