set off
phrasal verbset off
set something off
to make a bomb, etc. explode 使(炸弹等)爆炸 to make an alarm start ringing 使(警报)响起;拉响(警报) to start a process or series of events Topics Change, cause and effectc2引发;激起 to make something more attractive or easy to notice by being placed near it 衬托;使显得更突出(或更漂亮)
set somebody off (doing something)
to make somebody start doing something such as laughing, crying or talking 使某人笑(或哭、说等)起来