The state of idle file descriptors is known since the pollcache service is notified once when it changes.

空闲文件描述符的状态是已知的，因为在状态改变时会通知 poll 缓存服务。

youdao

The merge executes twice, once when it receives control from the lower start node, and again when it receives control from the join.

merge执行了两次，在接收到来自下面的开始节点的控制时会执行一次，而在接收到来自join的控制时会再次执行。

youdao

We will keep in mind your requirement for... and shall contact you once (when) it is available.

我方会留心你方对…要求，一旦有货将立即同你方联系。

youdao

It can be treated when found early, but once it grows the chances of survival drop sharply.

VOA: special.2009.05.13

Another thing is that, when once an invention is made, it tends to be copied all over the world.

另外，一旦一个发明诞生，它就会被模仿并应用于世界各地。

耶鲁公开课 - 金融市场课程节选

So whether we finish it today, or more likely when we finish it up on Friday, once we get passed isoelectronic atoms, that's it, that's all you need to study for this first exam.

因此，我们也许今天讲完，或者更有可能周五讲完，无论如何，就到我们讲完等电子原子为止，这是你们第一次考试所需要准备的全部内容。

麻省理工公开课 - 化学原理课程节选

What conservatives most want is an uncomplicated system that taxes income only once (when it is earned) at one low rate.

FORBES: Magazine Article

The club hosts the Sky cameras once again when it plays West Ham - on one of the holiest days of the year, Good Friday.

BBC: News | UK | Bells ring out against Sunday soccer

Hillsborough County, in fact, has sided with the winner in every election since 1960, save once, when it chose George Bush senior over Bill Clinton, and no president has won Florida without also winning Hillsborough.

ECONOMIST: The swing states: Florida