????:1?????????????:??????????

2???????

3???????

4????????

5??????

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

????

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

1??;

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

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

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

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