Given the task definition and input, reply with output. 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: Hal was led to a room in the back of the clinic. Sentence2: A beautiful nurse asked him to open his mouth wide. Sentence3: She shoved in a hard wooden board so he wouldn't bite his tongue. Sentence4: Hal became a bit concerned when she brought out a large plastic tube. Sentence5: The nurse reassured him and took x-rays of his mouth.
Nurse, Hal