as keen as mustard
非常熱衷、充滿熱情
口語·形容非常熱衷
英文釋義
to be very enthusiastic or eager about something
例句
The new intern is as keen as mustard, always volunteering for extra tasks.
典故來源
源自19世紀英國，芥末味道辛辣刺激，比喻人的熱情和積極性像芥末一樣強烈，常見于口語。