单项选择题
A.22.5 B.25 C.22.3 D.27.9
A.10-20;0.0.946-0.950 B.18-24;0.0.954-0.958 C.15-22;0.0.961-0.965 D.4.4-6.5;0.951-0.955
A.55/45 B.52.5/47.5 C.50/50