Question: who plays alex in the mummy tomb of the dragon emperor
[{'answer': 'Luke Ford', 'provenance': [{'wikipedia_id': '957331', 'title': 'The Mummy: Tomb of the Dragon Emperor', 'start_paragraph_id': 1, 'start_character': 481, 'end_paragraph_id': 1, 'end_character': 490, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '957331', 'title': 'The Mummy: Tomb of the Dragon Emperor', 'start_paragraph_id': 14, 'start_character': 0, 'end_paragraph_id': 14, 'end_character': 38, 'bleu_score': 0.6147881529512641, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16411731825696736982}, 'section': 'Section::::Cast.\n'}]}]