????2???????????? ????2????淨(jìng)????

???????-????????飬???????42????????????????????????????????????е???????????淨(jìng)???????????????1?Σ???????2?Σ???????????顢?????????????????????????

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

?淨(jìng)????

?????????36????????????????????????????????????????????????????20????y???????

?????t??м???????????????????в????????

1. ????????????褺?С???????????50%

2. ??????????????????????????????30%

3. ???????????????С?????????????20%

4. ???????????????????????????????10%

5. ΤС????????????????????????30%

6. ?????????????????????????????30%

?淨(jìng)??????

??????????顢?????????????????????????