at the drop of a hat片語KK [æt ðə drɑp ʌv ə hæt] /æt ðə dɹɑp ʌv ə hæt/發音片語1立刻、毫不猶豫地、隨時口語He would quit his job and move abroad at the drop of a hat.他會毫不猶豫地辭掉工作，搬到國外去。