?? ????????????:?????
????:1?????????:????
2?????????
3??????????
4?????vx
5??????????
6???13?????????????????,??????????,6????13???15?????,???????,???????????????????,?????????????????????????????????????????????,????(?????30????50????????????,???????????????80??)??????????,6????13?????????????15????????????40??80?,?100??,????????????250????400???????6????????????13?15?????????????(?????????????)
??:???