set off 动身，起程；使爆发 If you want to catch that train we'd better set off for the station immediately. 你要是想赶上那班火车，咱们就最好马上动身去火车站。 What time are you planning to set off tomorrow? 你打算明天几点钟启程? They've set off on a journey round the world. 他们已经开始环游世界。 Do be careful with those fireworks; the slightest spark could set them off. 这些烟火要格外小心，稍有火星就能引起爆炸。 The first atom bomb was set off over Hiroshima. 第一颗原子弹是在广岛上空爆炸的。 The burning gas was easy to set off an explosion. 燃烧的煤气容易引起爆炸。
