?? ???????????????
????:1?????????????:??????
2?????vx
3????????????
4?????????
5?????
?????8????19??? ??,???????????8??19??18????:
??,8???????????????????19??20???????20??20????,???????????????????????????????????????????????????????????????????????????????????????????????????????????????????????????,?????,???????????????????????????????????????????????(100~200??)??????(??????????????30~60????????????,?????80?????),???????
????:
1.?;
2.??????,??;
3.??????????????????,?????,????????????;
4.?????????????????????,???????? ??????:???