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

2?????vx

3?????????

4?????????

5??????????

?????????11????22????????????? ??22?,?????????????????“??”???????,?????

????????,??????????,??,21???????????????????“??”???????????????,???????????????????,??“????????????”??,????????????????????

?????????????????,“??????????”??,?????????????????“???????????,???”?“?????”???

???,“?????”?????????????????????????,????????,??,??????,????????????????????,????????????

????????,???????????,????????????????????????????????????????????????,????????,???????????????,????????????“????????????????”??????????????????,?????????????,???

??????21????????????????????????,????????,??“??????”?????????????(?????????????????) ?????????????????????????????:??????