● Kev tsim khoom siv
ENCO muaj cov khoom siv hauv tsev tsim khoom hauv HangZhou thiab Huzhou nroog. Peb lub hauv paus tsim khoom yog cov cuab yeej siv nrog lub ntiaj teb cov cuab yeej ua haujlwm siab tshaj plaws thiab cov neeg ua haujlwm tau zoo, thiab peb tsom rau cov khoom siv crystallization thiab evaporation, nrog rau lwm yam khoom siv tseem ceeb rau 20 xyoo dhau los.
