A mission begins with a warning order. 一项任务以预先号令(WARNO)开始。
The labour administrative departments shall issue a warning and order them to correct. 由劳动行政部门给予警告,责令改正;
In addition, it may be used to express a solemn statement, reminder, frank talk, warning, order, emphasis, etc, which, as its discursive functions, are grounded on the attention-drawing function. 此外,它还可以表达郑重告知、提醒、坦陈、警告、命令、强调等话语功能,而这些功能都是以提请听话人的注意为基础的。
But a word of warning is in order : You should remember what your priorities are. 不过提醒一句:你应该记住自己的首要目的是什么。
It's primarily useful because it doesn't show a warning; in order to achieve that effect without a function you 'd have to check whether the string is defined every time. 该函数是极为有用的,因为它不显示警告信息;为了不使用函数而又达到这个目的,您必须检查是否每次都定义了字符串。