????:1??????????:?????????

2??????????

3??????????

4?????sn

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

????????9??????6????????????????? (?? ??????????? ??)5??,???(?“?”),??,????????????,???????

5????,??????????????? ? ???????????????????? ??

??????????????,???????????????????5????????????,??????????????2?????????

16???????????????????30?????,??????????????????????????????????????????????????,????????????????????????????????????????,??????????????“????????????????”???????

“??????????????,?????????,??????????????????????”????????????,??,?????????????

???,???????????????????????????,????“???,??,?????”?????????,?????????????????,???

“???,?????????????”??,?????????????,??????????????(???)

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