abstractionn.抽象;抽象概念;心不在焉
abstraction hierarchy抽象层次
abstraction principle抽象原则
abstraction structure抽象结构
abstraction cognition抽象认识
abstraction of pillar回采矿柱
abstraction of pillars回采煤柱
abstraction refinement抽象求精
abstraction experiment抽象实验
abstraction of utility效用抽象
Abstraction metallurgy提炼冶金