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

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

3????????

4?????wx?

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

????12???20??????????????? (????????????? ???)????20?,??,??????????????,???????????,???????4.8?????????????,????????????

12???20?,????????????????

“?,?????????????,???????1000?????(?????,?????)????????400???????????????????”?????????????????????????,??????????,????????3.76????????????,??130????16??????????????,????143?????????????,???173?????????????,??

??,??(??????????????????),??????????????????????????????????????????????“??????????????”??????????,??????????“?????”??????“??????????????123??????????,??????????????????”

????????????,?7??,????????????4?????????????????,???“?????????????6-8??,?????????,?????????,?????????????????????”??????????????,???????83???????????????,???????

???????????????????????????,??????????,?,???????????????????????????,?5???????????????????,????700???????????????,????????15??????????????????,????

“?????????,?????????????????,?????????????,???????”????,???,?????,?,?,?????????,?????????????????????4????????(?????????????)

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