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

2?????

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

4???????

5?????????????

??2????????????3?????? ?????,??,2?3????????????20??????4?????20????,???????????????????????????5~6?????????7~8??????,?????,??????????????????????6~8???????9~10?????????????????????????????????????????????????????????????????7~8??????9?,????9???????????????????10???????

2??4?20?5??20??????,?????????????????????????????????????5~6??????7~8??????,????????????????????????6~8???????????9~10??;??????????????????????????????????????????????7~8??????9????,?9????????????????10???????????

??

???????:

1????????????,?????;

2????????????,???????????;

3?????????????????????????,??????????????;

4????,???

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