Once events are safely in the past, this idea seems to become less alarming.

一旦事件稳稳地尘封为历史，这种想法似乎就变得不那么令人惊慌了。

《柯林斯英汉双解大词典》

The significant difference between this and the prior scenario is that we want to have the timer events occur at a specific time, such as "once an hour at 10 minutes past the hour".

此场景和前一场景的重要区别在于，我们希望计时器事件在特定时间发生，如“每小时一次，在整点后 10 分钟发生”。

youdao

Events of the past month show, once again, why you should never put too much faith in the opinions of Wall Street experts and analysts.

过去一个月的各种事件再次证明，为什么永远不应该盲从华尔街专家与分析师的观点。

youdao

Ms Moreland said an independent review will take place into "past events" at the school once the police investigation is complete.

BBC: Chethams School of Music

Despite having hosted several major international events over the past two years, Ghana has once again been slow off the starting line.

BBC: Billboards and hawkwers in Accra

There are always enough intelligence indicators so that once you go back -- knowing the pattern of actual events -- it becomes possible to predict the past with 20-20 hindsight.

CNN: Benghazi blame game is useless