at a stroke

1. 一下子

She solved the problem at a stroke.

她一下子解决了问题。

on the stroke

1. 准时地

They arrived on the stroke.

他们准时到达。


习惯用语stroke sb. down1.平息某人的怒气stroke sb. [sb.'s hair] up (the wrong way)1.倒捋毛发, 触怒某人, 犯某人之忌