单项选择题
A.矩形弯管导流叶片B.风帽的制作C.消声器D.检查门
A.5%,1B.5%,2C.10%,1D.10%,2
A.±1,0.03,0.04B.±2,0.03,0.05C.±2,0.02,0.04D.±1,0.02,0.05