The morning was cold and clear. A yellow bus came around the corner and stopped near a wood  . A coach asked the students to get off the bus. Girls began to gather by the starting line. One of them is a young, little girl. She had prepared for this running race for the whole summer. She looked around at the other girls, noticing how she was different. There was a break in the silence, and everyone started to run. After about twenty-five minutes, every runner finished the race except the girl. She was still running for the next forty minutes. As she came near the finishing line, she saw her parents, classmates and the coach. They shouted her name and told her not to stop until the end. The sweat   was flowing down her face. She kept on running until she crossed the line. I was that girl, and that was the first time I had finished a cross-country race  . Finishing this race made me realize that I could do anything with my own strength. After that, I took more hard work to practice running. I was not a natural-born runner, but I want to become one. I continued to struggle   with every run. Now I run much faster than before and become more and more confident. I am so thankful for running because it has helped make me who I am today. What's the main idea of the passage?
We should practice running if we want to be more confident. We should do things that we are good at. We should keep on doing what we want to, no matter whether we are good at it or not. We could become the best if we keep on practicing.