mark off

基本解釋

Lily's score was far above this year's cut-off mark and was successfully enrolled by her dream university.
今年高考，麗麗的成績(jī)超過(guò)分?jǐn)?shù)線(xiàn)很多，順利地進(jìn)入了理想中的大學(xué)。
But one of the young success stories from last year -- Facebook founder Mark Zuckerberg -- dropped off the list altogether。
而去年創(chuàng)造成功神話(huà)的年輕富豪、Facebook的創(chuàng)始人馬克?扎克博格今年則跌出該榜。
edu.sina.com.cn
To mark off-limit areas, simply place a Virtual Wall at a doorway or other opening and adjust the infrared beam setting to the distance of the opening.
為了紀(jì)念限制區(qū)，簡(jiǎn)單地在門(mén)口或其他開(kāi)放的虛擬墻和調(diào)整紅外線(xiàn)光束設(shè)置開(kāi)幕的距離。

First they use 30-foot yellow ropes to mark off two 30-foot rows of corn.
FORBES: Adventures in Corn
The latest move by Larry Ellison, taking in Hewlett-Packard cast-off Mark Hurd, and surely nudging out co-president Charles Phillips is already proving brilliant.
FORBES: Redundancy In Oracle's Upper Ranks

If you mark off a piece or length of something, you make it separate, for example by putting a line on it or around it.