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

????:????50????????:?????????

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

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

?:

1?????????????????;

2?????;

3????;

4???

???:??????