A.200Hz
B.2000Hz
C.20000kHz
D.20000Hz
E.200000kHz
[单选题]超声波是人耳听不到的声波,其频率大于A.1000HzB.2000HzC.20kHzD.2MHzE.10kHz
[单选题]超声波是指声波频率高于多少的声波A.200HzB.2000HzC.20000kHzD.20000HzE.200000kHz
[单选题]超声波是指声波频率高于多少的声波A.200HzB.2000HzC.20000kHzD.20000HzE.200000kHz
[单选题]超声波是指频率高于多少的声波A.200HzB.2000HzC.10000HzD.20000HzE.100000Hz
[单选题]超声波是指频率高于多少的声波?( )A.200HzB.2000HzC.10000HzD.20000HzE.100000Hz
[单选题]超声波是指频率高于多少的声波?( )A.200HzB.2000HzC.10000HzD.20000HzE.100000Hz
超声波是指频率高于多少的声波?( )A. 200HzB. 2000HzC. 10000HzD. 20000HzE. 100000Hz
[单选题]人耳能听到的声波频率为A.20~2000HzB.20~20000HzC.200~2000HzD.2000~20000HzE.20~200000Hz
[单选题]超声的声波频率应大于A.2000HzB.20000HzC.50000HzD.5000HzE.10000Hz
[单选题]关于超声波的频率,下列哪项正确A.2000HzB.5000HzC.10000HzD.15000HzE.25000Hz