be completely indifferent
英 [bi kəmˈpliːtli ɪnˈdɪfrənt]   美 [bi kəmˈpliːtli ɪnˈdɪfrənt]  
无动于衷

例句

Whom I am, I do not believe that you can be completely indifferent at that moment wait until the answer to riddle is madeknown.

我是谁，等到谜底揭晓的那一刻，我不相信你还可以无动于衷。