?? ???4.2?? ????????????20????
????:1????v:??????????
2?????600
3?????
4??????????
5???????????
?1???2?????????? ??,?:01????02????????????12??40??(?43.81???,??81.27????)??4.2???,?20??
??:?????????? ??????????????:???1???2?????????? ??,?:01????02????????????12??40??(?43.81???,??81.27????)??4.2???,?20??
??:?????????? ??????????????:??????:1????v:??????????
2?????600
3?????
4??????????
5???????????
?1???2?????????? ??,?:01????02????????????12??40??(?43.81???,??81.27????)??4.2???,?20??
??:?????????? ??????????????:??