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

2???????v

3????????

4???????

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

??2??????2? ?,???2?1??,?1????????????31??????????????????????????????????,?????,?????????????????????????????????19??????????????????

????????????:?????????????,???1????????????????????????31????????????,??????????,?????????????????????????????

?,???2??????????1?????????,?????,??

???,??????1???????31??????,??????,???????,???

??????????,????????????????????????????????????,??????????,???????????

????,??????????2????????????1?????????????????????,?,?????

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