?? ??21?????6?????????
????:1???????:?????????????
2???????
3?????????????
4??????
5?????
?????6???11?????? (??????? ?)?,6?8???,??????11???????????,???????41??????????????42?,???????????????????????????????21??????6?????????
??,???????????,???,????????????6??????9??????,11???????????????17??????????????,?????,????????????????
?????????????????????????,?,????????????????,?????????,?????????,??????????????,?,?,????
??????????,?????????????????,??????,????,??,???????????????????,?????????????,??????????(?????????) ???:?????