For the fans,it will be a once-in-a-lifetime opportunity to join the celebrations and see the world's greatest football players compete at home in Africa.

VOA: standard.2010.02.10

And then other people are really excited because it's a once-in-a-lifetime opportunity

而另外一些人真的很兴奋，因为这是一个一生只有一次的机会，

正准备奥运会 - SpeakingMax英语口语达人