run off 逃跑；流掉；迅速离开。to有方向的指向。
run off to跑向。 run off one's feet累得精疲力竭,疲于奔命；be run off one's feet忙得不可开交。

【例句】
I wonder where that guy's run off to, she thought distractedly.
这家伙不知道跑到哪儿去啦，她怅惘地想。

He was run off his feet with jobs to do.
他忙得脚不沾地。