比较机械波和电磁波( ) A.二者都传递介质

比较机械波和电磁波( )

A.二者都传递介质 B.二者都传递能量

C.二者传播都需要介质 D.二者的传播都不需要介质

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比较机械波和电磁波( ) A.二者都传递介质

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