???????? ???????? ??? ?????? ?????? ??????? ??????????????? ????? ?????? ??? ????? ??????????? ???? ??????? ???????:???? ??? ??????? ????? ????? ????? ???? ??????? ?????????? ??? ??? ????? ???????? ??? ???????? ?? ????? ???? ????? ?????? ?? ?????? ?????????.Classification is a indicator to determine the contractor's ability and competence in keepin