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

2?????vx

3??????????

4?????

5???????

????2??????????????6??? (?? ???)2?6????????????,?????????,????????????????????????????

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

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

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

?????:???