I keep the timer set for 30 minutes, and the alarm beeps for 20 seconds when it goes off.

基本上我总是设定30分钟的倒数计时，大约20秒的闹铃。

youdao

Separating the profiles from the actual alarms is brilliant, because it lets me quickly set up a "nap" alarm (i.e, a one-time alarm) using one of my existing profiles, so it takes mere seconds.

将情景档案与实际使用的闹铃分来可谓神来一笔。 这样一来，我就可以利用我已有的情景档案来快速设置一个“午睡”闹铃（即一次性闹铃），只需短短几秒即可完成。

youdao

When the alarm is triggered, a window comes up on the phone screen saying that in approximately 10 seconds, there will be a quake of a certain strength.

在警报响起时，手机屏幕上会弹出一个窗口，上面的文字显示说，大约在10秒后，会发生一定级别强度的地震。

youdao

And then you can issue a silent alarm where in a few seconds or minutes somebody will show up to the gate and question that particular passenger.

CNN: Facing up to airport security fears

Revelations waited for them like all the silent seconds on a digital alarm clock before the shrieking starts or else like a land mine.

NPR: Excerpt: 'Estrellas y Rascacielos'