economic life
磨损
经济开采期限
经济寿命
经济批量
经济生命
符合经济效益的使用年限
经济年限
经济寿年
economic life of tractor
Economic Life Prediction
economic limit cumulative produc-tion
economic limit initial oil production
economic limit of water method
Economic Limit Oil-Bearing Area
Economic Limit Reserves
economic limit water cut
the economic life of the bridge