if there is a fine line between one thing and another, they are very similar although the second thing is bad.
There's a thin line between courage and foolishness. (often + between)
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。