Final answer:
The sentence in question, "The girl recited the poem beautifully," is an example of active voice, where the subject performs the action. It is not passive, so it doesn't need to be changed.
Step-by-step explanation:
The sentence "The girl recited the poem beautifully" is in active voice. In this sentence, the subject (the girl) is performing the action (reciting the poem). In active sentences, the subject does the action. By contrast, a passive construction would place the subject as the recipient of the action and might read, "The poem was beautifully recited by the girl," though this is not the case here. Comparatively, using active voice results in a clearer and more direct statement, which can make the writing more engaging and lively.