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

????:????:???????600????

????6?????????15?????????? ??,????6???15??18???:16???,????????????,??????6?????16??,???????????????????????????????????????????????????????????????????????????????????????????????????35~36???,??,????????37~39?,??40???????????

17-19?????????????????????,??????????????????????????????????17??????,??????????????????????????????37~39??,????40??????

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

?:

1?????;

2????????????????;

3??????????????????????????;

4???

??:???