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

2??????????

3????????

4???????sn

5???????

???????????? ???????????

?????????????2???????????????????6???????????? (???????? ???? ????)?????????????6?????,?,?,????????

????,???,????18.7????,???????????????19.4%????????4160???(????????)????,??5.7%?

????,??,????????10.16??????????,???????????280??,???????????????2700??????????????????;??4.04???,2?????????????1?126????3600?,?????

????????????……??????????????????????,??????????????(?????)????,????,?118??,?4490????????????,??(????) ???????:?????