提供一个简短的故事，要求你在其中插入一个情节或事件。
Once upon a time, there was a little girl named Mary. She had a red bike, and she loved to ride it around the park near her house.
One day, while Mary was riding her bike, she saw a lost dog wandering around the park. Mary quickly got off her bike and tried to approach the dog. However, the dog was scared and kept running away from Mary. Mary knew she had to do something to help the dog, so she decided to ask for help from the park ranger. Together, they were able to catch the dog and find its owner. Mary felt proud of herself for being brave and helping the lost dog.