12.2 单质 Simple substances 12.2.1物理和化学性质 Physico-chemical property 12.2.2 矿物资源和金属单质制备 Natural recourses,elementary substance abstraction 12.2.3用途概述 Generality of application 上页 下页 目录 返回 12.2 单质 Simple substances 12.2.1 物理和化学性质 Physico-chemical property 12.2.2 矿物资源和金属单质制备 Natural recourses, elementary substance abstraction 12.2.3 用途概述 Generality of application