每日英语俚语5

know something inside out
对某事相当了解；对某事认识很透彻

During an interview, he was sharp, combative and a bit relieved to be talking about things he knows inside out.
在接受采访时，他看起来相当的有斗志，谈到自己熟知的事务时有如释重负的感觉。