????? ?? ? 1??? ???? ????? ????? 25? ???. ???? ???? ???? ‘???’? ???? ?????? 0.2～0.25%? ???? ???? ??? ?????? 0.5～0.7%?? 0.5%?, ????????(HTS) ???? 0.25～0.4%?? 0.25～0.3%? ????. ????? “??? ?????? ?? ???? ???? ???? 0.05%??? ??? ?”??? “???? ?? ?? ??”??? ????.