?? ???????????????????
????:1?????????:??sn??
2??????????
3??????
4????????
5??????????????
?11?????????30?? ?11??30??,?,???????????????????12????????2?????4?????????????(????????)
????:???11?????????30?? ?11??30??,?,???????????????????12????????2?????4?????????????(????????)
????:??????:1?????????:??sn??
2??????????
3??????
4????????
5??????????????
?11?????????30?? ?11??30??,?,???????????????????12????????2?????4?????????????(????????)
????:??