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

2?????

3???400??

4?????vx

5???????

??12??????19????? (??????????????? ?????????)???19???,???????????

?,???????????????????,?????????????49.9%???????????????????????????????????????????????,????????,???????

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

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

????,????????,???11?????44.3????,????????????3.5%?(????) ?????:????????????????????