看到那则广告是我人生中的一个决定性时刻。

Seeing that advertisement was a ___decisive moment in my life.

最近，我们的执行董事会采取了一项决定性举措。

Recently, our Board of Executives has taken a ___decisive step.

他在危机期间的领导力被证明是具有决定性的。

His leadership during the crisis proved to be ___decisive.