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

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

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

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

????:???

??

??:???????????,??????????,??????????????