In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.

Sentence1: The elementary school was taking Peter's class to the aquarium. Sentence2: At half past eight they loaded onto the bus and started their trip. Sentence3: When they arrived at the aquarium, Peter was amazed. Sentence4: The museum even had a walk-through tunnel surrounded by water! Sentence5: Peter can't wait to go back again.
Peter's class, Peter, The elementary school