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

2?????sn

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

4??????????

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

????6??17???????????????? (??? ?????????)???????????????????????,????“??”???????????????????“??????”???,????2704????/?????????????,??????19%,?????????????,???

7?????????????????

????2??????????3????????????2??????????????,????????????????7??????????????????????????????????????????,??????????2????????????????;??????????????????3??????????;?????2?????????????????????????????1129??,??42%,?;???225??????????????,????????????,??????????,???????

????????????????,???2??????????,???????????,?,???21??????????

?

???,?:

???,???????????????19%?

??????,????????78.6%,150?????,?????????????????????????????????????,???,?????

????????????97????????????????,???????????????

?????,??,?????,??????????????????????????????????,???,???????????,??

?????????,?????????????????????????????????6???????????7????????,?????????????????(??????) ??????:??????????????