????????2???????????????14?????????,????????????,??“???????????”???????????

???????????,??,?????????,??????????,????????,????,???????(????????????? ????)

?:?????????????????

“??????????”????

?? ????????:???????? ??

????:1???????????:??????sn

2???????

3?????????

4???????

5?????????????

????????2???????????????14?????????,????????????,??“???????????”???????????

???????????,??,?????????,??????????,????????,????,???????(????????????? ????)

?:?????????????????