A little event, a word from someone, a disappointment in work, many things can trigger such mood swings.

一件极小的偶然事件，某个人的只言片语，工作中的失意等等，很多事都会引起情绪波动。

youdao

But to trigger the heart tripwires of a man, a movie has to focus on him staying true to his word, whether it's a promise made to a lover, a comrade-in-arms, or a sick grandson.

不过要想触动一个男人的心弦，电影的重点要在于信守诺言，不管这个承诺对象是恋人，战友还是生病的孙子。

youdao

When it hears the trigger word, it plays it back.

在听到触发字后，就会播放出来。

youdao

But there is, obviously, which is the very onerous actions that would be forced on the Congress by the sequestration -- forgive me for using that word -- by the trigger.

WHITEHOUSE: Press Briefing