???6?7????? (???? ???????)6?7????,?????????6???????????????(?)????????????????????

?????????600??,???????????1????,??????????????????????????,??,????????

6???7???????????????????,????????????????? ?? ??

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

??????????,???????????,????????????????????????????30???(?)

?????:??????????? ??“???????”????

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

????:1????????:????vx

2???????

3????????

4???????

5???????

???6?7????? (???? ???????)6?7????,?????????6???????????????(?)????????????????????

?????????600??,???????????1????,??????????????????????????,??,????????

6???7???????????????????,????????????????? ?? ??

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

??????????,???????????,????????????????????????????30???(?)

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