短語(yǔ)詞組短語(yǔ)semantic knowledge hierarchy 語(yǔ)義知識(shí)表述躰系knowledge base of class hierarchy 類(lèi)層次知識(shí)庫(kù)hierarchy knowledge extraction 層次知識(shí)獲取hierarchy of knowledge 位堦;認(rèn)知層級(jí) 返回 knowledge hierarchy