at one's wit's end   (TTS發音)

not knowing what to do next；quite at a loss不知所措；智窮技盡

    The soldier was at his wit's end when facing the danger. 面對危險，那個士兵不知如何是好。

    He had approached every friend and acquaintance for help in vain and he was at his wit's end. 他曾向每位朋友和熟人求助，但毫無結果，那時他真是一籌莫展。