decisive
单词辨析：
既可用于指人，又可用于指事物，指人时通常作表语。
I am quite decided about the issue.
对于该问题，我主意已定。
She spoke in a decided voice.
她语气坚定。
指人果断的；也可用于指事物，表示决定性的。
a decisive victory
决定性的胜利
He gave way to a younger, more decisive leader.
他让位于更年轻、更有决断力的领导者。
There is a decisive change in the whole policy.
整个方针发生了决定性的变化。
这两个词也都可表示“明确的，明显的”，用于此义时可以换用，但 decided 更为正式。
Her answer was a decided/decisive yes.
她的回答是明确的同意。
相关例句：
A decisive battle is impending ( or is imminent).
迫临决战。
The UK has played a decisive role in these negotiations.
英国在这些谈判中发挥了决定性的作用。
They have vowed a quick and decisive response.
他们立誓要给出一个快速果断的回应。
This is a time of decisive action and quick thinking
这个时候应该果断行动、快速反应。
The decisive goal arrived against the run of play
这个决定性的得分逆转了场上的局势。
In the course of negotiations, their statements and quotations are very clear, clear, firm and decisive.
在谈判的过程中，他们的陈述和报价都非常清楚、明确、坚决和果断。