Final answer:
The correct verb form to complete the sentence is 'entrevistaba'. It means 'was interviewing' in English.
Step-by-step explanation:
The correct verb form to complete the sentence is entrevistaba.
This is because the sentence is in the past tense and uses the imperfect tense to describe an ongoing action in the past. The verb entrevistaba means 'was interviewing' in English.
For example, 'Cuando Juan entrevistaba al actor, otro reportero le hizo una pregunta' translates to 'When Juan was interviewing the actor, another reporter asked him a question'.
Learn more about verb form conjugation in Spanish