fatal和vital的区别

fatal是致命的意思，而vital则是必不可少的意思，区别可以从以下例子看出：

It is fatal case, there are many people watch it, you are the vital witness, please help us to solve this problem. 这是致命的案例，有很多人在看，你是必不可少的见证人，请帮助我们解决这个问题。