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超声波与次声波

> 关于超声波，下列判断正确的是 A.超声波是频率大于20000Hz的声波 B.超声波可以在真空中传播 C.人听不到超声波 D.超声波在15℃的空气中传播速度大于340m/s

问题：

发布时间：2024-09-13

关于超声波，下列判断正确的是

A.超声波是频率大于20000Hz的声波
B.超声波可以在真空中传播
C.人听不到超声波
D.超声波在15℃的空气中传播速度大于340m/s

参考答案：

提问用户：Ji***OKu

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