背景噪声
参考答案:
被测量噪声源以外的声源发出的环境噪声的总和。房间无人占用,所有通风、空调等机电设备正常运行条件测得的噪声值。本方案中采用噪声评价评价曲线(NC曲线)进行评价。
A.电压表连接法是错误的
B.灯L1两端电压大于灯L2两端电压
C.电流表A1的示数大于电流表A2的示数
D.电流表A1和A2的示数相同
I really felt at his words . His words are really to me .
A.surprised ; surprising ; surprise
B.surprising ; surprised ; a surprise
C.surprised ; surprised ; surprising
D.surprised ; surprising ; a surprise