单项选择题
A.±2.5%B.+2.0%C.±1.5%D.±1.0%
A.49.03~980.7NB.1.961~49.03NC.< 1.961ND.> 980.7N
A.±2.5%B.±2.0%C.±1.5%D.±1.0%