Final answer:
The adverb in the sentence is 'eagerly,' as it describes how Jaime reads the books.
Step-by-step explanation:
In the sentence 'My cousin Jaime eagerly reads every new book in the popular series,' the word that is an adverb is 'eagerly.'
Adverbs are words that modify verbs, adjectives, or other adverbs, often ending in '-ly.' They can describe how, when, where, how often, or to what degree an action is performed. In this case, 'eagerly' describes how Jaime reads the books, conveying enthusiasm and keen interest.
In the sentence, 'My cousin Jaime eagerly reads every new book in the popular series,' the adverb is eagerly. An adverb modifies a verb, adjective, or another adverb. In this case, 'eagerly' modifies the verb 'reads' by describing how Jaime reads the books, indicating that he does so with enthusiasm or eagerness.