usable floor area短语¹⁴⁴⁹⁷²⁺² 基本例句 使用面积 It is the key for the reduction of construction initial energy use to reduce the embodied energy intensity and quantity in per usable floor area of the main materials. 降低主要建筑材料的内含能量强度值和单位建筑面积内建筑材料的使用量，是降低施工初始能耗的有效途径。 cnki