??????:7? ?7??8?????????

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

???2??16????????? ?,??,2?????????????16??????20?????17???????20?,?????????????????????????????????????????4~6?????7~8???????????????????;??????????????????????????7?????????8??

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

??:

1??????????????????????????????,??;

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

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

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

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