????:1?????????:????sn

2?????98??

3????????????

4?????

5?????xj??fg

?????????????????12????????????20?????????? ???,???????20?????????????

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

???????????????????????????????????,?????????????????????????????????????????????????????,9??????????????????5???????16??,???????????????????????,??????,???????????????,20????????????????

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

????????,?,???????????????,???“???????????????????”?

?????,21??,????(?????????????) ??????:??????????????????????