????????????8???????????
??????2??21??????? (?????????????????????? ??????)21?????????,?8????????????????
?????????????????,?????,?????,???????????????????????4?4???,?????????????????????????????????????,?????“????”??????????,???????,???????????
???????????????????,??,??????????????????????????????,??????“???”?????“1+N”?????????,??????????????,????????????????????,?????,??????,????,?????????,??????????????????????,????????????(?????????????)

??
???:????