decisively词根是：

decide

美 /dɪˈsaɪd/

英 /dɪˈsaɪd/

vt.

决定；解决；判决

vi.

决定，下决心

过去式 decided

过去分词 decided

现在分词 deciding

第三人称单数 decides

双语例句:

It is difficult for the manager to decide which of the two interviewees is more suitable for this job.

经理很难在这两个面试者中决定谁更合适这个职位。