?? ????:????????? ??????????
????:1?????????:??????
2??????
3?????????
4?????sn
5???????????
??2??4??????????? (?????????? ????????????????? ??)“???????????,????????”?????????????????,???????????????????(??????),????????????,??????????????
?????????????,??????????,?????????????,??????????????
????,“???????,?????????????????????,??,?????????????”
???????????,?,????
???????????????????????,“?????????,?????????????????,??????”
?,????????????????“?????????????????????????????????????????????,???,????”?????????
?,“???????????,????,????????????????????,??????,???????????”
????????????????????,????????????????????2??????2???,????42.6??,???????4.9?????(????)
????????????????:????