图所示是一列横波在某一时刻的波形图,波沿x轴正向传播,波速是18m/s,则( )
A:波长是6cm,频率是1/3Hz
B:波长是8m,频率是9/4Hz
C:波长是10cm,频率是1.8Hz
D:波长是8cm,频率是4/9Hz
Would you please explain the problem them?
计算2log510+log50.25= ( )