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 pressed, I'm overly surprised by what is a very mechanical and certainly menacing engine bark.

按动启动按钮，我惊奇的意识到引擎发出的是一种非常机械感并近乎邪恶的吼声。

youdao

Once pressed, you'll see a? Symbol appear in the address bar and you can simply enter your search query and hit Return.

一旦按下，您会看到一个？象征出现在地址栏，您可以只需输入您的搜索查询，并按返回。

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