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

2???????

3??????????

4?????????

5????????

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

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

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

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

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

?????????????????:??????????????