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

2?????vx

3???????

4???????

5??????????

????????????7?22???????? (? ??)??22??,7?????22??????????????23???,?????,?(?????????)?????????????????

????,7???22???????23??????????,????,???????(??30~50?????)?????????,??22????????????????????23????????,23??????,?100~150?(?????50~70?????),???50~100??,???????????????15~50????,?????????????1~15???

?????????,???????????????????????????????????22??10??30????????,??????????????(???)

???:???