???:???
“??????”_????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??
???“???????????”,????????
???“???????????”,????????
??
????:
1???????:??sn??
2??????????
3????????????
4?????????
5??????
???:???
????
6
%
???:??