I love to tell the story about how I met my best friend---- Tiger. We met at the school fair. Each year, all the fourth-grade classes hold a school fair. Everyone in the fourth-grade works at the fair. Some sell ice cream, drinks and snacks. Others take care of the little children who ride the rides. I got the second job and I've never regretted it, because that's where I met Tiger. My job was to help little children get on the back of a little horse. I kept telling the children to wait their turn and holding ice cream for them while they rode about. One thing was clear to me. I was growing older and should be more responsible. Suddenly, a boy came to the horse. He took the little horse's reins! The horse stopped, and the girl on its back started to fall. I was trying to reach the girl when I saw Tiger go by my legs. It held the horse's reins and pulled the horse away from my legs. I caught the girl just before we both hit the ground. The girl sat on top of me. She was laughing at the ice cream on my face. The horse's reins were in Tiger's mouth! Thanks to Tiger's fast action, I saved the little girl. We were both heroes. And Tiger, the fastest dog I've even known became my new best friend. Tiger helped to save the little girl on the horse by   _  .
going fast by the writer's legs trying to catch the little girl holding the reins with its mouth riding the little horse around