????:???
??“????600?????”
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??????
??
???????????!??????
???????????!??????
??
????:
1?????600?????:??????????
2???????
3?????????
4???????
5?????????
????:???
????
6
%
???:??