The trigger, once pressed, dispatches a custom event.

触发器被触发之后，就会分派一个定制的事件。

youdao

Once, he pressed Scott about whether he was committed to the hard work it would take.

NEWYORKER: A Pickpocket��s Tale

Once this rat pressed the correct lever, its brain activity was delivered as electrical stimulation into the brain of the second rat - designated the "decoder".

BBC: One rat brain 'talks' to another using electronic link

There's no word yet on when the pause button will be pressed once more, but you can probably assume it won't be until Q1 2013 at the earliest.

ENGADGET: Facebook pauses efforts to launch ad network