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

2???????

3??????????

4?????????

5??????????

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

?????

??????:

1???;

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

3?????,?,?;

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

??????:???