单项选择题
A.26.55≈26.5B.32.4501≈32.4C.15.450≈15.5D.14.05001≈14.1
A.2%B.-2%C.0.20gD.-0.20g
A.55dB(A)B.60dB(A)C.65dB(A)D.70dB(A)