辨析：set about ,set out ,set down ,set upThey now ____to climb the mountain.这句话中用哪一个?为什么?

辨析：set about ,set out ,set down ,set upThey now ____to climb the mountain.这句话中用哪一个?为什么?
辨析：set about ,set out ,set down ,set up
They now ____to climb the mountain.这句话中用哪一个?为什么?

辨析：set about ,set out ,set down ,set upThey now ____to climb the mountain.这句话中用哪一个?为什么?
set about 开始,散布
set out 出发,开始,装饰,陈列,测定,宣布,移植,陈述
set down 放下,使下车,使着陆,登记,把...归于,击败,把...看作,记下
set up 设立,竖立,架起,升起,装配,创(纪录),提出,开业
所以选set out

选择set out,出发