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

1.???????

????????2?λ??????????????????????????????2?λ??????

????????????4????????????????????????????????????????????????????????

2.????????

?????????δ???????????????????????????????????“??μ??”????????±???????????????????????????????????“???????”???????????

???????????????????????????????令??????λ?ú??y???;???????????б???????????????

????????????ò????????

a.???????50???飬100???????

b.??????80???飬200???????

c.??????150???飬200???????

d.?????????300???飬300???????