?? ?????????“??????????????????”?????
????:1???????:??????
2??????????
3???????????
4???????
5?????????
?????????????9??????????????21??????????? 9????????21??,????????????????????“????????????????”????????????????????????“??????????”?????????????,?????????????????,???,???????????????????????????????????????????????????????????,??,???????????????????????????????????????,?“?????????????+??”??????,?“?”?????????????????????????
??????
9?????????????????????????????????????????21?????,??????“????”??(????????)?????60?????????,????????????????????????,????MCN???“???????????????????”?“?????”???????,????????????,?????????????“??????????”???????????,??????????????,??????????(???????)
?????:???