?? ???????????8????????????

????:1???????:??????????
2?????????????
3?????????
4???????????
5???92?????
??????????????????????????2??????????????????????21?????? (??????? ?????)21???????,?????????8??????????
??????,??,??????????????????????,?????4???????????4???????????????,?????????????????????????????????,??????????“??????”??????????,????,????
??????????????,?????????????????,?????????,??“?????”?“1+N”???????????????,??,???????????????????,?????,????????????????????,??????,????????????????????????????,????????????,???????????(?)
????:????