??????
??????
??????
????????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??
?????????4??? 17???
?????????4??? 17???
??
????:
1?????????:?????????
2?????????
3???sn??
4???????
5?????????
????
6
%
???:??