?? ??????????????????
????:1???????:???????????
2?????
3?????sn
4??????????
5???92???
???11??????27????????????????????? (? ??)??27???????????????????,??????????????????,?,????
??????????????????????,??????????????????????????????????????????(??????????)????????
?????????????????20???????,??11???????????22??,????????????70????????,?????????6????
??300??,????????????8.6%??8.7%?????????????????????,?,???????????(?????????????????) ??????:?????????