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

???:?????