??????? ???????????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???,???,??????????????,??????,?,?????(???)