单项选择题
A.2.5 B.0.4 C.30% D.3% E.无法计算
A.9000 B.3010 C.4010 D.3760 E.6000
A.208×66/192×50 B.192×50/208×66 C.208/(208+50) D.208/400-50/116 E.资料不全,元法计算