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

?????????????????е?????????????飬??????е?Ψ?????????????????????????????2000??5000??10000???????Σ???????????20???????Ч????????????????????20%?????????2-6?????????????????10%????????7?????????14??19??20???????????????????20%???????14????19?????????????30%?????????????????20???????50%?????????????????????????????????δ???????????????????????????????ID??????????1?Σ??????????