??????????? ???????15.3?

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

???2??17??? (? ??????????????????)????????????????17?????,?????????,2?13?16???????????,??????,???72???15.3?,???????;???????????????????????????10??48???6.5?~10.9???????,?;????????????????4??

??,???? ?

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

????????????????????2?????????18???????????2???????22???????,???,???????????????????,????????????2???19???????????2?20??,???????????,?????????????,???????????????,????,?????????????(??)

???:??