A.聲波進(jìn)入墻體后波長(zhǎng)變長(zhǎng)B.聲波進(jìn)入墻體后頻率增加C.聲波進(jìn)入墻體后周期減小D.聲波進(jìn)入墻體后聲速增加
A.0.034mB.0.34mC.0.017mD.0.17m
A.0.3315mB.0.3435mC.0.3525mD.0.4535m