mark-off system删除方式
mark-off沾污
mark-off line划痕
mark off for cutting切割划线
mark broken or off标记损坏或脱落
jamming grade mark off干扰等级划分
mark off spheres of influence划分势力范围
mark off two historical epochs区分两个历史时代
I mark off each day我替这些日复一日消逝的时光
PHRASAL VERB（动词词组） 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. 画线分隔出
He used a rope to mark off the circle.
他用一根绳子把这个圈围了起来。