????:1???????:?????????

2??????

3?????????

4????????????

5????????????

???2??????????????15???? (???? ??????????)??????15??,2?,????????????,???????

??,???????????????,????????????????????????????????????????????????????????????????,?????2???????(2????16??28??)???????

??????????,2???????,????????????????????????????????,?????????????????,????????????????????,??????????????????????????????????,??????????

2?????????????????,??,??????????,?????????,??????,??,?????????????????

????????????,2???????,????,???????,?????????????????,???????,???????????????????????????????????????,??,????????????,??2????,??,??(???????????????????) ???????????:?????