???12????11??????????????????????????? ???“??”????,?????????????,??????,???,????????????????????????????????????????,????,???????????????????????????????????,??,?????????????

??????????????????,???????????????????????????,????,????

??,?????????????,????“????”“????????????”“????????????????????”“??????????????”“???”“?????”?????,????“???”“???”??????“????????”???????,???“???????”“????”“??”???????????????????????,????“????”“?????????????????????”“???????”?????????????????,?????????????,??????????,????????????,???,?“???????????”“??????”“????”“??????????????????”???????????????????????,??,?????????,?? ????????:????????? “????+v”_????

?? ?????????????????

????:1?????+v:????vx

2????????

3?????

4??????????????

5????????

???12????11??????????????????????????? ???“??”????,?????????????,??????,???,????????????????????????????????????????,????,???????????????????????????????????,??,?????????????

??????????????????,???????????????????????????,????,????

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