英语翻译The mystery was explained when the Commanding Officer ad

the mystery是explain的宾语.when是时间状语从句.你把主句和从句的位置交换一下,你的句子就容易理解了：When the Commanding Officer admitted (said) that one half of the station did not know what the other half was doing,the mystery was explained.
-------翻译：
指挥官承认,station裏面有一半人不知道另一半人在干什麼,这时谜底就解开了/ 谜底就得到解释了.

你的问题很好。对语法扣得很细。谈谈自己的看法：

1。主句“The mistery was explained" 后面接的是状语从句，由"when"引导。
2。主句是被动形态，如果后面是形式主语，也应该用 “by that" 来引导。

不知道解释到了没有。满意别忘采纳哈！...