????????? ?????? ?????? ?? ?????????? ??? ??? ????????? ????? ? ??????? ?????? ?????? ???-?????. ??? ????? ?????????? ???? ???????? ????????? ? ???? ????? ???????? ? ????? ????.??????? ???????????? ? ?????? ??????? ? ???? ?????? ???????????? ?????????The lesser the concentration of these kinds of trace things, the “whiter” or maybe more colourl