"at the first sign of trouble"是什么意思?

"at the first sign of trouble"是什么意思? at the first sign sign at the first desk onlY the firsT sigN of lifE .{YTNE→ENTY【Enty】} first of all first the first at first的区别 the first of April.是什么意思? the first of October是什么意思 the first letter of 是什么意思 the first of January是什么意思 The first,the first of all ,first of all ,at the first 之间主要区 怎么区分the first,the first of all ,first of all ,at the first,t which is the traffic sign of the following是什么意思