decisive /dɪˈsaɪsɪv/

　　adj。果断的，决定性的，坚定的

　　It means that someone is able to decide sth。quickly and with confidence； or refers to a particular situationwhich is very important for the final result。

　　它指的是某人能迅速且自信地决定某事；或指某种对最终结果非常重要的特定情况。

　　Our teamneedsa more decisive team leader。

　　我们的队伍需要一位更加果断的队长。

　　We all know that she has played a decisive role in the negotiations。

　　众所周知，她在谈判中起到了关键作用。