单项选择题
A.±1.5% B.±2.5% C.±5% D.±3%
A.2档 B.靠近两端各选1档 C.中间选2档 D.靠近两端及中间可选3~4档
A.0.8~1.1 B.1.1~1.2 C.1.2~1.3 D.0.7~1.2