Have you been to the Great Wall? It is known as the eighth （奇迹）of the world.
Every year, thousands of （游客）from around the world visit the Great Wall, and I am one of them. Here, I saw many volunteers helping the （年长的）carry heavy bags, taking photos for tourists, and （回答） people's questions. They looked tired, but they didn't take a rest. It was at that （时刻） when I suddenly saw a lost child crying （大声地）. I walked up to him and asked what happened. He told me that he couldn't find his mother. After （讨论）, we decided （联系） his mother through a phone call. 20 minutes later, the boy's mother （到达）, and she expressed her gratitude to us continuously. This made me understand the （乐趣） of helping others.
