单项选择题
A.增加B.不变C.减少D.无法判断
A.250nmB.181.2nmC.125nmD.90.6nm
A.当n1>n2>n3时,不考虑额外光程差B.当n1<n2<n3时,不考虑额外光程差C.当n1>n2<n3时,必须考虑额外光程差D.当n1<n2>n3时,不考虑额外光程差