?????????????

1??????=12%(????????8—10%)?

2?????????=????/????X100%=20%;

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

4?????????=1/5??????????=5mm;

5????????????????;

6??????????=1/4??????????=20mm;

7????????????????????10%?????15%;

8???????????=1/4?????=1/5??;

9?????????????????;

10?????????????????;

11???????????????;

12???????????????????????;

13?????????????????????????????

14??????????????????????????????????????