◎ 天知道 tiān zhīdào

(1) [God knows!Heaven knows!]∶天才知道,也就是说,谁也不知道。感叹用语,近似“天晓得”

(2) [difficult to understand or distinguish;I don't know this from that]∶表示难以理解或无法分辩

天知道那是怎么一回事