参考范文：
One Sunday morning, there were some people in Zhongshan Park. At a stand, a woman was buying an ice-cream when a young man behind her snatched her handbag away. Hearing the shouting“stop him”, a few people began to run after him. There was an old man sitting quietly on a bench nearby and as the snatcher was running past him, the old man quickly picked up his umbrella and put it between the snatcher’s legs ,so the young man fell down on the ground hard. Soon two policemen came in a police car and arrested him. At last, the woman thanked the old man, and the people around praised the old man for his cleverness.