unanswerable
adjective uk/ʌnˈɑːn.sər.ə.bəl/ us/ʌnˈæn.sɚ.ə.bəl/
(CLEARLY TRUE)
formal（论点或说法）无可争辩的，不容反对的
If an argument or claim is unanswerable, people cannot disagree with it because it is so clearly true.
In economic terms the need to reduce inflation is unanswerable. 从经济学角度考虑，需要降低通货膨胀是毋庸置疑的。
(WITHOUT AN ANSWER)
（问题）没有答案的，无法回答的
(of a question) without an answer
As to how long this war will last, it's an unanswerable question. 至于这场战争会持续多久，没有人知道答案。