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

2???????????

3?????????

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

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

???1?8?????????????????????? (?)1??7?9???????????????5??,?6.8???,??4?(??????????????,?????????????),???

?,?1?????????7??18???,?????202???????????????????????????????????252?????????,??4????;?500???

????,?,???4???????????,???????????????????????????????????????????????????????????????????????,?57??;?50?,???4??×5????,????????????????????????21?????????????????????30?????????;????????,????????????,??????,???(???)

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