economicality经济性economicaladj.节俭的；经济的；合算的economical efficiency of systems制度经济性economical and high-efficiency节能高效economical principle of thinking思维经济原则economical efficiency evaluation经济性评价economical and technique indices经济技术指标economically feasible technology经济适用技术economically inactive population经济上非活动人口Economical Use of Formal Methods形式化方法的经济使用economical principle on thinking思维经济原则economical landscape architecture节约型园林