No one has come up with a definitive answer as to why this should be so.

至于为什么该这样，还没有人想出确定的答案。

The study population was too small to reach any definitive conclusions.

被研究的人群太小，无法得出明确的结论。

Ian Macdonald's definitive book on The Beatles.

伊恩·麦克唐纳写的有关甲壳虫乐队的最权威的书。