Answer:
Her brother loves to bike, to swim and to go to the movies.
Step-by-step explanation:
In this sentence, the mistake lies in the fact that the list does not follow a parallel structure. When we are listing items, they all need to be structured in the same way in order to avoid confusion and cacophony. In this case, the items should be listed as infinitive verbs. By doing so, we make the sentence clearer and allow it to flow more easily.