????:?????
??“???sn??”
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??
????????????????:????????????????????? ????????
????????????????:????????????????????? ????????
??
????:
1????sn??:?????????
2???????
3????????
4???????
5???95??????
????:?????
????
6
%
???:??