?? ????????6????21?7??6?
????:1???????????:??????????
2?????????
3?????????
4?????????
5??????????
????????????????????????????,?????????????6??????,?,?????????????????,???????????6??21??????7????????????6???????????????????????????????
?1???????????????????,?,????10??????4???,?,????????????????????,?,??????????10????7????(???)?,???(??? ??)
???????:??