???Σ????????????
???/?????????
???е???10%????Щ?У?1%~2%???????????в???緢????
???УΡ??????????嵽?????顱?С??????Ρ?????????????????
 緢?
???????????????????Щ??t??С???????Щ???飬???飺
1.???С??飬??????????????
2.??鵥??飬????????????????
3.B?С??????磬????10~12??5~6??3~4??С????????B???8С??????
???
 ???Щ
??????о???е???10%????ЩУ?1%~2%???????????в??
????к?????????????????У??Ρ????嵽?????顱??С??????Ρ?????????
??? ??????
????????????????????20%~30%???80%????????С??????????????????θ?????ɡ
?ε??5~6???????и??????????3????????????Σ?Щζ??Ρ????轴?飬?????Σ??ζ????
ε??????????????ζ????ζ???????????ζ??????Σ?ζ????Щ??????Ρ?ɡ?ε??????
?ε?ζ?ζ????θ?????У??С?Щζ?????
???? 
??????????????????????? 0.6~0.8???Χ?60?????????
??????????????????????????????????????????
????????????????Щ?????β???????
?????????????????95%??????????????????
?????????????Щ??????????е?????????
? ??
????硢????????????
???磬?????????????????1500??????Щ???裬????????????????衣
??????????Щ???????硣??з??彡??ɡ????????????ζ??
?????????????????????????????????ɡ





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