??
????????2?17????????????? (? ???)??17???????????,??????,2????????????13??16??,?????,???72??????????15.3?,???;?????????????????10??48????????????????????6.5?~10.9??????,?;???????????4??????????????
??,???,??????????????????????????????????????????????
??2???????18??????2????22??????????????????,???????????,??????????????????????,????????2??19?2?20???????,??,????????????,????????????????????,????????,????(?)
??:?????????????????????
???????????????? ???????15.3??????????????