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

2??????????

3???????????

4????????

5??????????????

?????????????2??????21??????????????? (??? ???????????????????)??,????,????????????????????????????21??????????????,?,???,?,???????????“???????????”?????????????????????,??????????????????

????“?????????????????”???????????,??????????(??)

??????????2??????H?????????,????????????????????“????????????????”???????“??”????????????????????,???????????????????????,????????????????????????????,????????????????“??”????????????????????,???????????????

???????,????????,??“????????????????????”??,??????????????????????????,??1????????????,????360°?????????,???????,???????????,???????

???????????,“?????????”????????????,?????,????????????,?????(?????????????????????)

????:??