One possible version
：
Hello, everyone. The Nanjing 2014 Youth Summer Olympic Games will be held from August 16 thto 28 th. It’s one of the world’s most important events. I’m proud to have the chance to be a volunteer. As students, we should learn about manners and be polite to friends from all over the world. Nanjing is developing quickly, so it’s necessary for everyone to protect the environment. For example, we should plant more trees to reduce pollution. I believe we can do something to make a big difference. Everyone should help make the event a big success.
Let’s act together! Thank you!
本篇书面表达应根据提纲内容写一篇演讲稿。可以使用be proud of, learn about, necessary等词。同时应选用合适的连接词或过渡词，使文章具有一定的连贯性。温馨提醒：考生必须认真查验是否有漏写情况，有无拼写错误及标点误用等。
【亮点说明】本文结构紧凑，准确运用时态。文章衔接连贯，运用了As students, for example, so等连词进行衔接。同时，本文中运用了大量的固定句式和短语，为文章增色不少。如:be proud to do, be polite to, all over the world, make a big difference等。作者还能准确运用不定式来表示目的，如： we should plant more trees to reduce pollution.