To remain calm and composed when inactive, and to act with swiftness, agility, and decisiveness when taking action.
比赛开始前，选手们静静地站在起跑线上，一旦发令枪响，便动如脱兔，冲了出去
Before the race, the athletes stood silently at the starting line; once the starting gun fired, they moved like escaping rabbits, dashing forward.
Next Idiom