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

2???????

3???????sn

4??????????

5??????

?????????????12?????????????????19???????????????? ????????????????,????18??????,????,??17??????????????,????????,???

???,??????????,??18?????????????????,?,????

??????????,??????(????9?????2?)???????????????,???????????????11????42?????????

????,??????????????????“???”???

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

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

?“??????”????????????????,2024?,????????????491???,????????????1.61?????????????????????,???????????????????????????,4????????????? ???????:???