Answer:
In the sentence "Olivia loves to travel, so we bought her a subscription to National Geographic magazine, an excellent source of trip ideas," there are two prepositional phrases:
Step-by-step explanation:
"to National Geographic magazine" - This prepositional phrase modifies the verb "bought" and tells us the recipient of the action.
"of trip ideas" - This prepositional phrase modifies the noun "source" and tells us the kind of ideas that the source provides.
A prepositional phrase is a group of words that begins with a preposition and ends with a noun or pronoun (called the object of the preposition). Prepositional phrases function as adjectives or adverbs in a sentence, modifying nouns or verbs and providing additional information.