un on
继续,继续下去；连续不断；流逝；涉及
run on
1.继续行进；继续航行：
The boat ran on smoothly.
小船顺利地继续向前航行.
2.喋喋讲个不休：
She will run on for hours about her romantic deeds.
提起她的风流韵事她能连续讲好几个小时.
3.(时间)流逝：
How time runs on!
时光过得多快呀!
4.继续下去：
Don't interrupt him.Let him run on.
别打断他的话,让他讲下去.
5.连写(字母等)：
The pupils are learning to run their letters on.
学生们正在学习把字母连起来写.
6.靠(某种动力或燃料)运转：
This kind of walking tractor runs on diesel oil.
这种手扶拖拉机靠柴油运转.
7.(使)撞在…上：
The ship ran on rocks.
轮船触礁了.
8.(谈话等)涉及；(脑子里)总是想着：
His talk ran on recent developments in science and technology.
他的讲话涉及科技的新动态.
Her mind keeps running on the college entrance examination.
她的脑子里总是想着高考.