if a situation, especially a job, is a bed of nails, it is difficult or unpleasant.
He resigned last week, describing the post as a bed of nails.
英语词组固定搭配大全包含18674条英汉双解词组，基本涵盖了全部常用英文词组、短语的翻译及用法，是英语学习的有利工具。