◎ 批郤导窽 pīxì-dǎokuǎn

[make penetrating criticism(like carving joints by skillful butcher);hit the nail on the head] 《庄子·养生主》:“依乎天理,批大郤,导大窽,因其固然。”在骨头接合的地方批开,没有骨头的地方则就势分解。比喻抓住关键,事情就能顺利解决