Q: 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: Ben went to the gas station to fill his gas tank. Sentence2: He drove on the highway afterwards. Sentence3: Since the gas tank had a hole on it, gas leaked out. Sentence4: Ben's car stopped working on the road. Sentence5: His friend had to tow his car.
A:
Friend, Ben