[经] comparative statement of monthly operative cost per unit

gōng zuò dān wèi měi yuè chéng běn bǐ jiào biǎo ㄍㄨㄥ ㄗㄨㄛˋ ㄉㄢ ㄨㄟˋ ㄇㄟˇ ㄩㄝˋ ㄔㄥˊ ㄅㄣˇ ㄅㄧˇ ㄐㄧㄠˋ ㄅㄧㄠˇ