帮我看看下面的一段英文有什么语法毛病啊?

改过了.语法错误不多,很好.
Last summer, I had a chance to go to Beijing as a volunteer for the 2008 Olympic game. This activity gave me a valuable lesson for my life. My job was to help those people from all over the world to get the places they want to go. At first, I felt a little nervous. But after three days, I became more comfortable. Although the task was very hard, there was actually still a lot of fun during those days. This activity provides me an opportunity to practice my English and improve my communication skills with people from different countries. Olympic game is a great event for everyone in the world. Last summer, when I was standing on the land of Beijing, it was my great honor to see this marvelous event during my life, I will never forget that memorable experience.