mark off something
— phrasal verb with mark us/mɑrk/verb [ T ]
to make or draw a line that separates one thing from another:
Sheep graze on lush pastures marked off by centuries-old hedge rows.
英语词典包含110679条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。