略知皮毛

Explanation: The surface of the metaphor a little known or little superficial knowledge 　　Usage: Verb-object type; as the predicate attribute; containing derogatory 　　Source: Qing Li Ruzhen "Flowers in the Mirror" 17 back: "Talented science scholar said it is still dealt with tangential cutting stare silent, not to mention we only Luezhipimao, dare Luan Tan, a laughing stock!" 　　Examples: We only ~ this can not be good at a conclusion. Thesaurus:  A little knowledge of non-, an ignorant person, have a nodding acquaintance with sb., Vice Shaocai