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

2???sn??

3???????????

4??????????

5?????

???????????9????27??????????????? (???)27??????,???????????,??,???1450?????????????????????1050???,??????????????????“????”???????????32%???????????????????????50%?

??????,?????,???????????????????????????,???????????4000?2700?????????????????,??????800?,?????????

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

????????????????????????????????????????????,???(?)?????????????????????????????????,??????????????????,????????????????5????(??????????)?11??????????????????(??????????)?21?,?1100???

?,???????????????????????????????????????4?????250???????(??????)“???????????????????”,?????????????,????????????

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