单项选择题
A.27dB B.29.2dB C.30dB D.36dB
A.-36VDC—-57VDC B.42VDV—58VDC C.180VAC—240VAC D.-45VDC—-60VDC
A.-48VDC B.220VAC C.RPS供电 D.TBBP530机柜供电
A.4级 B.6级 C.8级 D.10级
微信扫一扫,加关注免费搜题
