there's the rub
口語·書面·指出關(guān)鍵問題
例句
I want to travel, but there's the rub: I have no money.
典故來源
源自莎士比亞《哈姆雷特》中“To be, or not to be”獨白，“rub”指障礙或困難，后成為常用表達。