????:1??????:????????????

2??????????

3???????

4???sn??

5???????

??12???????????????????????????????????22? ??,??????22???,?????????????????????????????(?????????????????)?????????????24??????«?????»??????«???????????????»?

???????,???,?,????????????????,???24?????,??????????,??(?????????????????????????),???????????????1?????

???,123???,???????????,???????(???)??????????????????????????,???????,?????????????????????????

“??????”?????????????????????????????????«????????????????????????????»,“?????????”?????«??????????????»???12????? ????????????:????