??????:?????????????10???

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

???????????????????? ??2?????6??18???????????:

?,??,2?????6??20????8??????20??????,???????6~8?,??????????????,?10??;????????????????4~6?,???7~8?,??????10???????8????????,????0????,???????????6~8??

?:

1???;

2????;

3??????????????????????;

4??????????????

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