单项选择题
A.2% B.1% C.0.5% D.5%
A.-35dB B.-40dB C.-50dB D.-60dB
A.±5% B.±10% C.±15% D.±20%
A.3dB B.5dB C.10dB D.15dB
微信扫一扫,加关注免费搜题
