???????????12?6??? ??5?????????:12?5?????????????15??????????????????28?????????????????,??,??????????,??,?????,??,???4????????????????????,?1?????????????????,???????;3?,???1??,??2??????????????????????????????????

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

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

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

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

2?????200?

3????????

4?????vx

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

???????????12?6??? ??5?????????:12?5?????????????15??????????????????28?????????????????,??,??????????,??,?????,??,???4????????????????????,?1?????????????????,???????;3?,???1??,??2??????????????????????????????????

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

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