the whys and wherefores (of (something))
the reasons for something.
The movie doesn't spend much time worrying about the whys and wherefores of its stars' behavior.
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。