set off,set out,set about,set out的区别和用法?

set off,set out,set about,set out的区别和用法?
set off,set out,set about,set out的区别和用法?

set off,set out,set about,set out的区别和用法?
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 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.
set about:
开始,着手,与set out意思相近,但set out后加不定式,即set out to do sth,而set about后加 ing形式,即set about doing sth.

例句与用法:
1. You must set about your work at once.
你必须立即开始工作.

2. Do you know how to set about going on this work?
你知道怎样着手进行这项工作吗?