??? ??? ???? ?? ?????? ????? ?? ????? ?????? ?? ?????? ???????? ???? ?? ??? ????? ????? ??? ????? ??????? ???? ?? ???? ??????? ??.??????? ???????? ??????? How would you build and use templates and symbols for prevalent mechanical factors??????? ??? ????? ???? ??? ?? ???? ?????? ???? ?????? ?????? ???? ???? ???? ????? ??? ????? ???? ?????? ???? ????