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

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

????6?15????? ??????????????????,???????6?15?18????:?????????????,6??????????15??20??16?????????20????????????????????,??????????????????????????????????????????????????????????,?????????????????,?????(100~200?????)???(??30~50?????,???????????70?),??????

????

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

1??;

2??????????????,????????????;

3???,?????,??????;

4??????????????????????,????

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