[经] system of material product balances
wù zhì chǎn pǐn píng héng tǐ xì ㄨˋ ㄓˋ ㄔㄢˇ ㄆㄧㄣˇ ㄆㄧㄥˊ ㄏㄥˊ ㄊㄧˇ ㄒㄧˋ