set out出发，动身，开始。
例句
When they set out they were well prepared.
他们出发时有很充分的准备。
I set out to buy food.
我动身去买吃的。
He has achieved what he set out to do three years ago
他已经实现了他3年前的奋斗目标。
We have achieved what we set out to do.
我们已经达成了原初的目标。
We set out to find the truth behind the mystery.
我们开始着手揭开谜团背后的真相。
