set off set on set out区别

set off: 出发,侧重于去某个地方
例句与用法:
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.
They've set off on a journey round the world.
他们已经开始环游世界.
set on
v.
攻击, 前进, 怂恿, 使开始
而且这个句子里面不是set on的短语..set表被动.
意思是这东西经常被放在一个被叫做讲坛的突起的舞台上.
set out:
出发,开始,侧重于开始做某事,还有规划,展现的意思
例句与用法:
They succeeded in what they set out to do.
他们打算做的事已经做成了.