Final answer:
The verb 'no ver' should be used to fill in the blank in the given sentence.
Step-by-step explanation:
The appropriate verb to fill in the blank in the sentence is no ver, which means 'did not see' in English. The correct conjugation for the verb is 'vieron', which matches the subject 'mis padres'. Therefore, the sentence should read 'Mis padres no vieron la película anoche.'
Learn more about Spanish verbs