Question

highlight any word(s) that make up the verb. peter parker had been building a submarine in his basement.

Explanation:

The verb phrase "had been building" indicates an action that started in the past, continued for a period, and was ongoing at a specific past - time. In English grammar, verb phrases can consist of multiple words including auxiliary verbs and main verbs. Here, "had been" are auxiliary verbs and "building" is the main verb.

Answer:

had been building